class ListBuffer[A] extends AbstractBuffer[A] with SeqOps[A, ListBuffer, ListBuffer[A]] with StrictOptimizedSeqOps[A, ListBuffer, ListBuffer[A]] with ReusableBuilder[A, immutable.List[A]] with IterableFactoryDefaults[A, ListBuffer] with DefaultSerializable
A Buffer
implementation backed by a list. It provides constant time
prepend and append. Most other operations are linear.
- A
the type of this list buffer's elements.
- Annotations
- @SerialVersionUID()
- Source
- ListBuffer.scala
- See also
"Scala's Collection Library overview" section on
List Buffers
for more information.
- Alphabetic
- By Inheritance
- ListBuffer
- DefaultSerializable
- Serializable
- ReusableBuilder
- Builder
- StrictOptimizedSeqOps
- StrictOptimizedIterableOps
- AbstractBuffer
- Buffer
- Shrinkable
- Growable
- Clearable
- AbstractSeq
- Seq
- SeqOps
- Cloneable
- Cloneable
- Iterable
- AbstractSeq
- Seq
- Equals
- SeqOps
- PartialFunction
- Function1
- AbstractIterable
- Iterable
- IterableFactoryDefaults
- IterableOps
- IterableOnceOps
- IterableOnce
- AnyRef
- Any
- by UnliftOps
- by iterableOnceExtensionMethods
- by any2stringadd
- by StringFormat
- by Ensuring
- by ArrowAssoc
- Hide All
- Show All
- Public
- Protected
Instance Constructors
- new ListBuffer()
Value Members
- final def !=(arg0: Any): Boolean
Test two objects for inequality.
Test two objects for inequality.
- returns
true
if !(this == that), false otherwise.
- Definition Classes
- AnyRef → Any
- final def ##: Int
Equivalent to
x.hashCode
except for boxed numeric types andnull
.Equivalent to
x.hashCode
except for boxed numeric types andnull
. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. Fornull
returns a hashcode wherenull.hashCode
throws aNullPointerException
.- returns
a hash value consistent with ==
- Definition Classes
- AnyRef → Any
- def +(other: String): String
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toany2stringadd[ListBuffer[A]] performed by method any2stringadd in scala.Predef.
- Definition Classes
- any2stringadd
- final def ++[B >: A](suffix: IterableOnce[B]): ListBuffer[B]
Alias for
concat
Alias for
concat
- Definition Classes
- IterableOps
- Annotations
- @inline()
- final def ++:[B >: A](prefix: IterableOnce[B]): ListBuffer[B]
Alias for
prependedAll
.Alias for
prependedAll
.- Definition Classes
- SeqOps → IterableOps
- Annotations
- @inline()
- final def ++=(elems: IterableOnce[A]): ListBuffer.this.type
Alias for
addAll
- final def ++=:(elems: IterableOnce[A]): ListBuffer.this.type
Alias for
prependAll
- final def +:[B >: A](elem: B): ListBuffer[B]
Alias for
prepended
. - final def +=(elem: A): ListBuffer.this.type
Alias for
addOne
- final def +=:(elem: A): ListBuffer.this.type
Alias for
prepend
- final def --=(xs: IterableOnce[A]): ListBuffer.this.type
Alias for
subtractAll
Alias for
subtractAll
- Definition Classes
- Shrinkable
- Annotations
- @inline()
- final def -=(elem: A): ListBuffer.this.type
Alias for
subtractOne
Alias for
subtractOne
- Definition Classes
- Shrinkable
- Annotations
- @inline()
- def ->[B](y: B): (ListBuffer[A], B)
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toArrowAssoc[ListBuffer[A]] performed by method ArrowAssoc in scala.Predef.This conversion will take place only if A is a subclass of Option[Nothing] (A <: Option[Nothing]).
- Definition Classes
- ArrowAssoc
- Annotations
- @inline()
- final def :+[B >: A](elem: B): ListBuffer[B]
Alias for
appended
. - final def :++[B >: A](suffix: IterableOnce[B]): ListBuffer[B]
Alias for
appendedAll
. - final def ==(arg0: Any): Boolean
The expression
x == that
is equivalent toif (x eq null) that eq null else x.equals(that)
.The expression
x == that
is equivalent toif (x eq null) that eq null else x.equals(that)
.- returns
true
if the receiver object is equivalent to the argument;false
otherwise.
- Definition Classes
- AnyRef → Any
- final def addAll(xs: IterableOnce[A]): ListBuffer.this.type
Adds all elements produced by an IterableOnce to this list buffer.
Adds all elements produced by an IterableOnce to this list buffer.
- returns
the list buffer itself.
- Definition Classes
- ListBuffer → Growable
- final def addOne(elem: A): ListBuffer.this.type
Adds a single element to this list buffer.
Adds a single element to this list buffer.
- elem
the element to add.
- returns
the list buffer itself
- Definition Classes
- ListBuffer → Growable
- final def addString(b: StringBuilder): b.type
Appends all elements of this list buffer to a string builder.
Appends all elements of this list buffer to a string builder. The written text consists of the string representations (w.r.t. the method
toString
) of all elements of this list buffer without any separator string.Example:
scala> val a = List(1,2,3,4) a: List[Int] = List(1, 2, 3, 4) scala> val b = new StringBuilder() b: StringBuilder = scala> val h = a.addString(b) h: StringBuilder = 1234
- b
the string builder to which elements are appended.
- returns
the string builder
b
to which elements were appended.
- Definition Classes
- IterableOnceOps
- Annotations
- @inline()
- final def addString(b: StringBuilder, sep: String): b.type
Appends all elements of this list buffer to a string builder using a separator string.
Appends all elements of this list buffer to a string builder using a separator string. The written text consists of the string representations (w.r.t. the method
toString
) of all elements of this list buffer, separated by the stringsep
.Example:
scala> val a = List(1,2,3,4) a: List[Int] = List(1, 2, 3, 4) scala> val b = new StringBuilder() b: StringBuilder = scala> a.addString(b, ", ") res0: StringBuilder = 1, 2, 3, 4
- b
the string builder to which elements are appended.
- sep
the separator string.
- returns
the string builder
b
to which elements were appended.
- Definition Classes
- IterableOnceOps
- Annotations
- @inline()
- def addString(b: StringBuilder, start: String, sep: String, end: String): b.type
Appends all elements of this list buffer to a string builder using start, end, and separator strings.
Appends all elements of this list buffer to a string builder using start, end, and separator strings. The written text begins with the string
start
and ends with the stringend
. Inside, the string representations (w.r.t. the methodtoString
) of all elements of this list buffer are separated by the stringsep
.Example:
scala> val a = List(1,2,3,4) a: List[Int] = List(1, 2, 3, 4) scala> val b = new StringBuilder() b: StringBuilder = scala> a.addString(b , "List(" , ", " , ")") res5: StringBuilder = List(1, 2, 3, 4)
- b
the string builder to which elements are appended.
- start
the starting string.
- sep
the separator string.
- end
the ending string.
- returns
the string builder
b
to which elements were appended.
- Definition Classes
- IterableOnceOps
- def andThen[C](k: PartialFunction[A, C]): PartialFunction[Int, C]
Composes this partial function with another partial function that gets applied to results of this partial function.
Composes this partial function with another partial function that gets applied to results of this partial function.
Note that calling isDefinedAt on the resulting partial function may apply the first partial function and execute its side effect. For efficiency, it is recommended to call applyOrElse instead of isDefinedAt or apply.
- C
the result type of the transformation function.
- k
the transformation function
- returns
a partial function with the domain of this partial function narrowed by other partial function, which maps arguments
x
tok(this(x))
.
- Definition Classes
- PartialFunction
- def andThen[C](k: (A) => C): PartialFunction[Int, C]
Composes this partial function with a transformation function that gets applied to results of this partial function.
Composes this partial function with a transformation function that gets applied to results of this partial function.
If the runtime type of the function is a
PartialFunction
then the otherandThen
method is used (note its cautions).- C
the result type of the transformation function.
- k
the transformation function
- returns
a partial function with the domain of this partial function, possibly narrowed by the specified function, which maps arguments
x
tok(this(x))
.
- Definition Classes
- PartialFunction → Function1
- final def append(elem: A): ListBuffer.this.type
Appends the given elements to this buffer.
- final def appendAll(elems: IterableOnce[A]): ListBuffer.this.type
Appends the elements contained in a iterable object to this buffer.
- def appended[B >: A](elem: B): ListBuffer[B]
A copy of this list buffer with an element appended.
A copy of this list buffer with an element appended.
Example:
scala> val a = List(1) a: List[Int] = List(1) scala> val b = a :+ 2 b: List[Int] = List(1, 2) scala> println(a) List(1)
- B
the element type of the returned list buffer.
- elem
the appended element
- returns
a new list buffer consisting of all elements of this list buffer followed by
value
.
- Definition Classes
- StrictOptimizedSeqOps → SeqOps
- def appendedAll[B >: A](suffix: IterableOnce[B]): ListBuffer[B]
Returns a new list buffer containing the elements from the left hand operand followed by the elements from the right hand operand.
Returns a new list buffer containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the list buffer is the most specific superclass encompassing the element types of the two operands.
- B
the element type of the returned collection.
- suffix
the iterable to append.
- returns
a new collection of type
CC[B]
which contains all elements of this list buffer followed by all elements ofsuffix
.
- Definition Classes
- StrictOptimizedSeqOps → SeqOps
- def apply(i: Int): A
Gets the element at the specified index.
Gets the element at the specified index. This operation is provided for convenience in
Seq
. It should not be assumed to be efficient unless you have anIndexedSeq
.- Definition Classes
- ListBuffer → SeqOps → Function1
- Annotations
- @throws(cause = scala.this.throws.<init>$default$1[IndexOutOfBoundsException])
- def applyOrElse[A1 <: Int, B1 >: A](x: A1, default: (A1) => B1): B1
Applies this partial function to the given argument when it is contained in the function domain.
Applies this partial function to the given argument when it is contained in the function domain. Applies fallback function where this partial function is not defined.
Note that expression
pf.applyOrElse(x, default)
is equivalent toif(pf isDefinedAt x) pf(x) else default(x)
except that
applyOrElse
method can be implemented more efficiently. For all partial function literals the compiler generates anapplyOrElse
implementation which avoids double evaluation of pattern matchers and guards. This makesapplyOrElse
the basis for the efficient implementation for many operations and scenarios, such as:- combining partial functions into
orElse
/andThen
chains does not lead to excessiveapply
/isDefinedAt
evaluation lift
andunlift
do not evaluate source functions twice on each invocationrunWith
allows efficient imperative-style combining of partial functions with conditionally applied actions
For non-literal partial function classes with nontrivial
isDefinedAt
method it is recommended to overrideapplyOrElse
with custom implementation that avoids doubleisDefinedAt
evaluation. This may result in better performance and more predictable behavior w.r.t. side effects.- x
the function argument
- default
the fallback function
- returns
the result of this function or fallback function application.
- Definition Classes
- PartialFunction
- combining partial functions into
- final def asInstanceOf[T0]: T0
Cast the receiver object to be of type
T0
.Cast the receiver object to be of type
T0
.Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression
1.asInstanceOf[String]
will throw aClassCastException
at runtime, while the expressionList(1).asInstanceOf[List[String]]
will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.- returns
the receiver object.
- Definition Classes
- Any
- Exceptions thrown
ClassCastException
if the receiver object is not an instance of the erasure of typeT0
.
- def canEqual(that: Any): Boolean
Checks whether this instance can possibly equal
that
.Checks whether this instance can possibly equal
that
.A method that should be called from every well-designed equals method that is open to be overridden in a subclass. See Programming in Scala, Chapter 28 for discussion and design.
- that
the value being probed for possible equality
- returns
true if this instance can possibly equal
that
, otherwise false
- def className: String
Defines the prefix of this object's
toString
representation.Defines the prefix of this object's
toString
representation.It is recommended to return the name of the concrete collection type, but not implementation subclasses. For example, for
ListMap
this method should return"ListMap"
, not"Map"
(the supertype) or"Node"
(an implementation subclass).The default implementation returns "Iterable". It is overridden for the basic collection kinds "Seq", "IndexedSeq", "LinearSeq", "Buffer", "Set", "Map", "SortedSet", "SortedMap" and "View".
- returns
a string representation which starts the result of
toString
applied to this list buffer. By default the string prefix is the simple name of the collection class list buffer.
- Attributes
- protected[this]
- Definition Classes
- Iterable
- def clear(): Unit
Clears the contents of this builder.
Clears the contents of this builder. After execution of this method, the builder will contain no elements.
If executed immediately after a call to
result()
, this allows a new instance of the same type of collection to be built.- Definition Classes
- ListBuffer → ReusableBuilder → Builder → Clearable
- def clone(): ListBuffer[A]
Create a copy of the receiver object.
- final def coll: ListBuffer.this.type
- returns
This collection as a
C
.
- Attributes
- protected
- Definition Classes
- Iterable → IterableOps
- def collect[B](pf: PartialFunction[A, B]): ListBuffer[B]
Builds a new list buffer by applying a partial function to all elements of this list buffer on which the function is defined.
Builds a new list buffer by applying a partial function to all elements of this list buffer on which the function is defined.
- B
the element type of the returned list buffer.
- pf
the partial function which filters and maps the list buffer.
- returns
a new list buffer resulting from applying the given partial function
pf
to each element on which it is defined and collecting the results. The order of the elements is preserved.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def collectFirst[B](pf: PartialFunction[A, B]): Option[B]
Finds the first element of the list buffer for which the given partial function is defined, and applies the partial function to it.
Finds the first element of the list buffer for which the given partial function is defined, and applies the partial function to it.
- pf
the partial function
- returns
an option value containing pf applied to the first value for which it is defined, or
None
if none exists.
- Definition Classes
- IterableOnceOps
Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10)
Example: - def combinations(n: Int): Iterator[ListBuffer[A]]
Iterates over combinations of elements.
Iterates over combinations of elements.
A combination of length
n
is a sequence ofn
elements selected in order of their first index in this sequence.For example,
"xyx"
has two combinations of length 2. Thex
is selected first:"xx"
,"xy"
. The sequence"yx"
is not returned as a combination because it is subsumed by"xy"
.If there is more than one way to generate the same combination, only one will be returned.
For example, the result
"xy"
arbitrarily selected one of thex
elements.As a further illustration,
"xyxx"
has three different ways to generate"xy"
because there are three elementsx
to choose from. Moreover, there are three unordered pairs"xx"
but only one is returned.It is not specified which of these equal combinations is returned. It is an implementation detail that should not be relied on. For example, the combination
"xx"
does not necessarily contain the firstx
in this sequence. This behavior is observable if the elements compare equal but are not identical.As a consequence,
"xyx".combinations(3).next()
is"xxy"
: the combination does not reflect the order of the original sequence, but the order in which elements were selected, by "first index"; the order of eachx
element is also arbitrary.Note: Even when applied to a view or a lazy collection it will always force the elements.
- returns
An Iterator which traverses the n-element combinations of this list buffer.
- Definition Classes
- SeqOps
Seq('a', 'b', 'b', 'b', 'c').combinations(2).foreach(println) // List(a, b) // List(a, c) // List(b, b) // List(b, c) Seq('b', 'a', 'b').combinations(2).foreach(println) // List(b, b) // List(b, a)
Example: - def compose[R](k: PartialFunction[R, Int]): PartialFunction[R, A]
Composes another partial function
k
with this partial function so that this partial function gets applied to results ofk
.Composes another partial function
k
with this partial function so that this partial function gets applied to results ofk
.Note that calling isDefinedAt on the resulting partial function may apply the first partial function and execute its side effect. For efficiency, it is recommended to call applyOrElse instead of isDefinedAt or apply.
- R
the parameter type of the transformation function.
- k
the transformation function
- returns
a partial function with the domain of other partial function narrowed by this partial function, which maps arguments
x
tothis(k(x))
.
- Definition Classes
- PartialFunction
- def compose[A](g: (A) => Int): (A) => A
Composes two instances of
Function1
in a newFunction1
, with this function applied last.Composes two instances of
Function1
in a newFunction1
, with this function applied last.- A
the type to which function
g
can be applied- g
a function A => T1
- returns
a new function
f
such thatf(x) == apply(g(x))
- Definition Classes
- Function1
- Annotations
- @unspecialized()
- final def concat[B >: A](suffix: IterableOnce[B]): ListBuffer[B]
Returns a new list buffer containing the elements from the left hand operand followed by the elements from the right hand operand.
Returns a new list buffer containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the list buffer is the most specific superclass encompassing the element types of the two operands.
- B
the element type of the returned collection.
- suffix
the iterable to append.
- returns
a new list buffer which contains all elements of this list buffer followed by all elements of
suffix
.
- Definition Classes
- SeqOps → IterableOps
- Annotations
- @inline()
- def contains[A1 >: A](elem: A1): Boolean
Tests whether this list buffer contains a given value as an element.
Tests whether this list buffer contains a given value as an element.
- elem
the element to test.
- returns
true
if this list buffer has an element that is equal (as determined by==
) toelem
,false
otherwise.
- Definition Classes
- SeqOps
- def containsSlice[B >: A](that: collection.Seq[B]): Boolean
Tests whether this list buffer contains a given sequence as a slice.
Tests whether this list buffer contains a given sequence as a slice.
- that
the sequence to test
- returns
true
if this list buffer contains a slice with the same elements asthat
, otherwisefalse
.
- Definition Classes
- SeqOps
- def copyToArray[B >: A](xs: Array[B], start: Int, len: Int): Int
Copy elements to an array, returning the number of elements written.
Copy elements to an array, returning the number of elements written.
Fills the given array
xs
starting at indexstart
with at mostlen
elements of this list buffer.Copying will stop once either all the elements of this list buffer have been copied, or the end of the array is reached, or
len
elements have been copied.- B
the type of the elements of the array.
- xs
the array to fill.
- start
the starting index of xs.
- len
the maximal number of elements to copy.
- returns
the number of elements written to the array
- Definition Classes
- IterableOnceOps
- Note
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
- def copyToArray[B >: A](xs: Array[B], start: Int): Int
Copies elements to an array, returning the number of elements written.
Copies elements to an array, returning the number of elements written.
Fills the given array
xs
starting at indexstart
with values of this list buffer.Copying will stop once either all the elements of this list buffer have been copied, or the end of the array is reached.
- B
the type of the elements of the array.
- xs
the array to fill.
- start
the starting index of xs.
- returns
the number of elements written to the array
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecatedOverriding()
- Note
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
- def copyToArray[B >: A](xs: Array[B]): Int
Copies elements to an array, returning the number of elements written.
Copies elements to an array, returning the number of elements written.
Fills the given array
xs
starting at indexstart
with values of this list buffer.Copying will stop once either all the elements of this list buffer have been copied, or the end of the array is reached.
- B
the type of the elements of the array.
- xs
the array to fill.
- returns
the number of elements written to the array
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecatedOverriding()
- Note
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
- def corresponds[B](that: collection.Seq[B])(p: (A, B) => Boolean): Boolean
Tests whether every element of this list buffer relates to the corresponding element of another sequence by satisfying a test predicate.
Tests whether every element of this list buffer relates to the corresponding element of another sequence by satisfying a test predicate.
- B
the type of the elements of
that
- that
the other sequence
- p
the test predicate, which relates elements from both sequences
- returns
true
if both sequences have the same length andp(x, y)
istrue
for all corresponding elementsx
of this list buffer andy
ofthat
, otherwisefalse
.
- Definition Classes
- SeqOps
- def corresponds[B](that: IterableOnce[B])(p: (A, B) => Boolean): Boolean
Tests whether every element of this collection's iterator relates to the corresponding element of another collection by satisfying a test predicate.
Tests whether every element of this collection's iterator relates to the corresponding element of another collection by satisfying a test predicate.
- B
the type of the elements of
that
- that
the other collection
- p
the test predicate, which relates elements from both collections
- returns
true
if both collections have the same length andp(x, y)
istrue
for all corresponding elementsx
of this iterator andy
ofthat
, otherwisefalse
- Definition Classes
- IterableOnceOps
- def count(p: (A) => Boolean): Int
Counts the number of elements in the list buffer which satisfy a predicate.
Counts the number of elements in the list buffer which satisfy a predicate.
- p
the predicate used to test elements.
- returns
the number of elements satisfying the predicate
p
.
- Definition Classes
- IterableOnceOps
- def diff[B >: A](that: collection.Seq[B]): ListBuffer[A]
Computes the multiset difference between this list buffer and another sequence.
Computes the multiset difference between this list buffer and another sequence.
- that
the sequence of elements to remove
- returns
a new list buffer which contains all elements of this list buffer except some of occurrences of elements that also appear in
that
. If an element valuex
appears n times inthat
, then the first n occurrences ofx
will not form part of the result, but any following occurrences will.
- Definition Classes
- StrictOptimizedSeqOps → SeqOps
- def distinct: ListBuffer[A]
Selects all the elements of this list buffer ignoring the duplicates.
Selects all the elements of this list buffer ignoring the duplicates.
- returns
a new list buffer consisting of all the elements of this list buffer without duplicates.
- Definition Classes
- SeqOps
- def distinctBy[B](f: (A) => B): ListBuffer[A]
Selects all the elements of this list buffer ignoring the duplicates as determined by
==
after applying the transforming functionf
.Selects all the elements of this list buffer ignoring the duplicates as determined by
==
after applying the transforming functionf
.- B
the type of the elements after being transformed by
f
- f
The transforming function whose result is used to determine the uniqueness of each element
- returns
a new list buffer consisting of all the elements of this list buffer without duplicates.
- Definition Classes
- StrictOptimizedSeqOps → SeqOps
- def drop(n: Int): ListBuffer[A]
Selects all elements except the first
n
ones.Selects all elements except the first
n
ones.- n
the number of elements to drop from this list buffer.
- returns
a list buffer consisting of all elements of this list buffer except the first
n
ones, or else the empty list buffer, if this list buffer has less thann
elements. Ifn
is negative, don't drop any elements.
- Definition Classes
- IterableOps → IterableOnceOps
- def dropInPlace(n: Int): ListBuffer.this.type
Removes the first
n
elements from this list buffer.Removes the first
n
elements from this list buffer.- n
the number of elements to remove
- returns
this list buffer
- Definition Classes
- Buffer
- def dropRight(n: Int): ListBuffer[A]
The rest of the collection without its
n
last elements.The rest of the collection without its
n
last elements. For linear, immutable collections this should avoid making a copy.Note: Even when applied to a view or a lazy collection it will always force the elements.
- n
the number of elements to drop from this list buffer.
- returns
a list buffer consisting of all elements of this list buffer except the last
n
ones, or else the empty list buffer, if this list buffer has less thann
elements. Ifn
is negative, don't drop any elements.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps
- def dropRightInPlace(n: Int): ListBuffer.this.type
Removes the last
n
elements from this list buffer.Removes the last
n
elements from this list buffer.- n
the number of elements to remove
- returns
this list buffer
- Definition Classes
- Buffer
- def dropWhile(p: (A) => Boolean): ListBuffer[A]
Selects all elements except the longest prefix that satisfies a predicate.
Selects all elements except the longest prefix that satisfies a predicate.
The matching prefix starts with the first element of this list buffer, and the element following the prefix is the first element that does not satisfy the predicate. The matching prefix may be empty, so that this method returns the entire list buffer.
Example:
scala> List(1, 2, 3, 100, 4).dropWhile(n => n < 10) val res0: List[Int] = List(100, 4) scala> List(1, 2, 3, 100, 4).dropWhile(n => n == 0) val res1: List[Int] = List(1, 2, 3, 100, 4)
Use span to obtain both the prefix and suffix. Use filterNot to drop all elements that satisfy the predicate.
- p
The predicate used to test elements.
- returns
the longest suffix of this list buffer whose first element does not satisfy the predicate
p
.
- Definition Classes
- IterableOps → IterableOnceOps
- def dropWhileInPlace(p: (A) => Boolean): ListBuffer.this.type
Drops the longest prefix of elements that satisfy a predicate.
- def elementWise: ElementWiseExtractor[Int, A]
Returns an extractor object with a
unapplySeq
method, which extracts each element of a sequence data.Returns an extractor object with a
unapplySeq
method, which extracts each element of a sequence data.- Definition Classes
- PartialFunction
val firstChar: String => Option[Char] = _.headOption Seq("foo", "bar", "baz") match { case firstChar.unlift.elementWise(c0, c1, c2) => println(s"$c0, $c1, $c2") // Output: f, b, b }
Example: - def empty: ListBuffer[A]
The empty iterable of the same type as this iterable.
The empty iterable of the same type as this iterable.
- returns
an empty iterable of type
C
.
- Definition Classes
- IterableFactoryDefaults → IterableOps
- def endsWith[B >: A](that: collection.Iterable[B]): Boolean
Tests whether this list buffer ends with the given sequence.
Tests whether this list buffer ends with the given sequence.
- that
the sequence to test
- returns
true
if this list buffer hasthat
as a suffix,false
otherwise.
- Definition Classes
- SeqOps
- def ensuring(cond: (ListBuffer[A]) => Boolean, msg: => Any): ListBuffer[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toEnsuring[ListBuffer[A]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- def ensuring(cond: (ListBuffer[A]) => Boolean): ListBuffer[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toEnsuring[ListBuffer[A]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- def ensuring(cond: Boolean, msg: => Any): ListBuffer[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toEnsuring[ListBuffer[A]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- def ensuring(cond: Boolean): ListBuffer[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toEnsuring[ListBuffer[A]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- final def eq(arg0: AnyRef): Boolean
Tests whether the argument (
that
) is a reference to the receiver object (this
).Tests whether the argument (
that
) is a reference to the receiver object (this
).The
eq
method implements an equivalence relation on non-null instances ofAnyRef
, and has three additional properties:- It is consistent: for any non-null instances
x
andy
of typeAnyRef
, multiple invocations ofx.eq(y)
consistently returnstrue
or consistently returnsfalse
. - For any non-null instance
x
of typeAnyRef
,x.eq(null)
andnull.eq(x)
returnsfalse
. null.eq(null)
returnstrue
.
When overriding the
equals
orhashCode
methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2
), they should be equal to each other (o1 == o2
) and they should hash to the same value (o1.hashCode == o2.hashCode
).- returns
true
if the argument is a reference to the receiver object;false
otherwise.
- Definition Classes
- AnyRef
- It is consistent: for any non-null instances
- def equals(o: Any): Boolean
Checks whether this instance is equal to
that
. - def exists(p: (A) => Boolean): Boolean
Tests whether a predicate holds for at least one element of this list buffer.
Tests whether a predicate holds for at least one element of this list buffer.
- p
the predicate used to test elements.
- returns
true
if the given predicatep
is satisfied by at least one element of this list buffer, otherwisefalse
- Definition Classes
- IterableOnceOps
- def filter(pred: (A) => Boolean): ListBuffer[A]
Selects all elements of this list buffer which satisfy a predicate.
Selects all elements of this list buffer which satisfy a predicate.
- returns
a new list buffer consisting of all elements of this list buffer that satisfy the given predicate
p
. The order of the elements is preserved.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def filterImpl(pred: (A) => Boolean, isFlipped: Boolean): ListBuffer[A]
- Attributes
- protected[collection]
- Definition Classes
- StrictOptimizedIterableOps
- def filterInPlace(p: (A) => Boolean): ListBuffer.this.type
Replace the contents of this list buffer with the filtered result.
Replace the contents of this list buffer with the filtered result.
- p
the filtering predicate
- returns
this list buffer
- def filterNot(pred: (A) => Boolean): ListBuffer[A]
Selects all elements of this list buffer which do not satisfy a predicate.
Selects all elements of this list buffer which do not satisfy a predicate.
- pred
the predicate used to test elements.
- returns
a new list buffer consisting of all elements of this list buffer that do not satisfy the given predicate
pred
. Their order may not be preserved.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def finalize(): Unit
Called by the garbage collector on the receiver object when there are no more references to the object.
Called by the garbage collector on the receiver object when there are no more references to the object.
The details of when and if the
finalize
method is invoked, as well as the interaction betweenfinalize
and non-local returns and exceptions, are all platform dependent.- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.Throwable])
- Note
not specified by SLS as a member of AnyRef
- def find(p: (A) => Boolean): Option[A]
Finds the first element of the list buffer satisfying a predicate, if any.
Finds the first element of the list buffer satisfying a predicate, if any.
- p
the predicate used to test elements.
- returns
an option value containing the first element in the list buffer that satisfies
p
, orNone
if none exists.
- Definition Classes
- IterableOnceOps
- def findLast(p: (A) => Boolean): Option[A]
Finds the last element of the list buffer satisfying a predicate, if any.
Finds the last element of the list buffer satisfying a predicate, if any.
- p
the predicate used to test elements.
- returns
an option value containing the last element in the list buffer that satisfies
p
, orNone
if none exists.
- Definition Classes
- SeqOps
- def flatMap[B](f: (A) => IterableOnce[B]): ListBuffer[B]
Builds a new list buffer by applying a function to all elements of this list buffer and using the elements of the resulting collections.
Builds a new list buffer by applying a function to all elements of this list buffer and using the elements of the resulting collections.
For example:
def getWords(lines: Seq[String]): Seq[String] = lines flatMap (line => line split "\\W+")
The type of the resulting collection is guided by the static type of list buffer. This might cause unexpected results sometimes. For example:
// lettersOf will return a Seq[Char] of likely repeated letters, instead of a Set def lettersOf(words: Seq[String]) = words flatMap (word => word.toSet) // lettersOf will return a Set[Char], not a Seq def lettersOf(words: Seq[String]) = words.toSet flatMap ((word: String) => word.toSeq) // xs will be an Iterable[Int] val xs = Map("a" -> List(11,111), "b" -> List(22,222)).flatMap(_._2) // ys will be a Map[Int, Int] val ys = Map("a" -> List(1 -> 11,1 -> 111), "b" -> List(2 -> 22,2 -> 222)).flatMap(_._2)
- B
the element type of the returned collection.
- f
the function to apply to each element.
- returns
a new list buffer resulting from applying the given collection-valued function
f
to each element of this list buffer and concatenating the results.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def flatMapInPlace(f: (A) => IterableOnce[A]): ListBuffer.this.type
Replace the contents of this list buffer with the flatmapped result.
Replace the contents of this list buffer with the flatmapped result.
- f
the mapping function
- returns
this list buffer
- def flatten[B](implicit toIterableOnce: (A) => IterableOnce[B]): ListBuffer[B]
Converts this list buffer of iterable collections into a list buffer formed by the elements of these iterable collections.
Converts this list buffer of iterable collections into a list buffer formed by the elements of these iterable collections.
The resulting collection's type will be guided by the type of list buffer. For example:
val xs = List( Set(1, 2, 3), Set(1, 2, 3) ).flatten // xs == List(1, 2, 3, 1, 2, 3) val ys = Set( List(1, 2, 3), List(3, 2, 1) ).flatten // ys == Set(1, 2, 3)
- B
the type of the elements of each iterable collection.
- returns
a new list buffer resulting from concatenating all element list buffers.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def fold[A1 >: A](z: A1)(op: (A1, A1) => A1): A1
Applies the given binary operator
op
to the given initial valuez
and all elements of this list buffer.Applies the given binary operator
op
to the given initial valuez
and all elements of this list buffer.For each application of the operator, each operand is either an element of this list buffer, the initial value, or another such application of the operator.
The order of applications of the operator is unspecified and may be nondeterministic. Each element appears exactly once in the computation. The initial value may be used an arbitrary number of times, but at least once.
If this collection is ordered, then for any application of the operator, the element(s) appearing in the left operand will precede those in the right.
Note: might return different results for different runs, unless either of the following conditions is met: (1) the operator is associative, and the underlying collection type is ordered; or (2) the operator is associative and commutative. In either case, it is also necessary that the initial value be a neutral value for the operator, e.g.
Nil
forList
concatenation or1
for multiplication.The default implementation in
IterableOnce
is equivalent tofoldLeft
but may be overridden for more efficient traversal orders.- A1
The type parameter for the binary operator, a supertype of
A
.- z
An initial value; may be used an arbitrary number of times in the computation of the result; must be a neutral value for
op
for the result to always be the same across runs.- op
A binary operator; must be associative for the result to always be the same across runs.
- returns
The result of applying
op
between all the elements andz
, orz
if this list buffer is empty.
- Definition Classes
- IterableOnceOps
- def foldLeft[B](z: B)(op: (B, A) => B): B
Applies the given binary operator
op
to the given initial valuez
and all elements of this list buffer, going left to right.Applies the given binary operator
op
to the given initial valuez
and all elements of this list buffer, going left to right. Returns the initial value if this list buffer is empty."Going left to right" only makes sense if this collection is ordered: then if
x1
,x2
, ...,xn
are the elements of this list buffer, the result isop( op( ... op( op(z, x1), x2) ... ), xn)
.If this collection is not ordered, then for each application of the operator, each right operand is an element. In addition, the leftmost operand is the initial value, and each other left operand is itself an application of the operator. The elements of this list buffer and the initial value all appear exactly once in the computation.
- B
The result type of the binary operator.
- z
An initial value.
- op
A binary operator.
- returns
The result of applying
op
toz
and all elements of this list buffer, going left to right. Returnsz
if this list buffer is empty.
- Definition Classes
- IterableOnceOps
- def foldRight[B](z: B)(op: (A, B) => B): B
Applies the given binary operator
op
to all elements of this list buffer and the given initial valuez
, going right to left.Applies the given binary operator
op
to all elements of this list buffer and the given initial valuez
, going right to left. Returns the initial value if this list buffer is empty."Going right to left" only makes sense if this collection is ordered: then if
x1
,x2
, ...,xn
are the elements of this list buffer, the result isop(x1, op(x2, op( ... op(xn, z) ... )))
.If this collection is not ordered, then for each application of the operator, each left operand is an element. In addition, the rightmost operand is the initial value, and each other right operand is itself an application of the operator. The elements of this list buffer and the initial value all appear exactly once in the computation.
- B
The result type of the binary operator.
- z
An initial value.
- op
A binary operator.
- returns
The result of applying
op
to all elements of this list buffer andz
, going right to left. Returnsz
if this list buffer is empty.
- Definition Classes
- IterableOnceOps
- def forall(p: (A) => Boolean): Boolean
Tests whether a predicate holds for all elements of this list buffer.
Tests whether a predicate holds for all elements of this list buffer.
- p
the predicate used to test elements.
- returns
true
if this list buffer is empty or the given predicatep
holds for all elements of this list buffer, otherwisefalse
.
- Definition Classes
- IterableOnceOps
- def foreach[U](f: (A) => U): Unit
Applies
f
to each element for its side effects.Applies
f
to each element for its side effects. Note:U
parameter needed to help scalac's type inference.- Definition Classes
- IterableOnceOps
- def fromSpecific(coll: IterableOnce[A]): ListBuffer[A]
Defines how to turn a given
Iterable[A]
into a collection of typeC
.Defines how to turn a given
Iterable[A]
into a collection of typeC
.This process can be done in a strict way or a non-strict way (ie. without evaluating the elements of the resulting collections). In other words, this methods defines the evaluation model of the collection.
- Attributes
- protected
- Definition Classes
- IterableFactoryDefaults → IterableOps
- Note
When implementing a custom collection type and refining
,C
to the new type, this method needs to be overridden (the compiler will issue an error otherwise). In the common case whereC =:= CC[A]
, this can be done by mixing in the scala.collection.IterableFactoryDefaults trait, which implements the method using iterableFactory.As witnessed by the
@uncheckedVariance
annotation, using this method might be unsound. However, as long as it is called with anIterable[A]
obtained fromthis
collection (as it is the case in the implementations of operations where we use aView[A]
), it is safe.
- final def getClass(): Class[_ <: AnyRef]
Returns the runtime class representation of the object.
- def groupBy[K](f: (A) => K): immutable.Map[K, ListBuffer[A]]
Partitions this list buffer into a map of list buffers according to some discriminator function.
Partitions this list buffer into a map of list buffers according to some discriminator function.
Note: Even when applied to a view or a lazy collection it will always force the elements.
- K
the type of keys returned by the discriminator function.
- f
the discriminator function.
- returns
A map from keys to list buffers such that the following invariant holds:
(xs groupBy f)(k) = xs filter (x => f(x) == k)
That is, every key
k
is bound to a list buffer of those elementsx
for whichf(x)
equalsk
.
- Definition Classes
- IterableOps
- def groupMap[K, B](key: (A) => K)(f: (A) => B): immutable.Map[K, ListBuffer[B]]
Partitions this list buffer into a map of list buffers according to a discriminator function
key
.Partitions this list buffer into a map of list buffers according to a discriminator function
key
. Each element in a group is transformed into a value of typeB
using thevalue
function.It is equivalent to
groupBy(key).mapValues(_.map(f))
, but more efficient.case class User(name: String, age: Int) def namesByAge(users: Seq[User]): Map[Int, Seq[String]] = users.groupMap(_.age)(_.name)
Note: Even when applied to a view or a lazy collection it will always force the elements.
- K
the type of keys returned by the discriminator function
- B
the type of values returned by the transformation function
- key
the discriminator function
- f
the element transformation function
- Definition Classes
- IterableOps
- def groupMapReduce[K, B](key: (A) => K)(f: (A) => B)(reduce: (B, B) => B): immutable.Map[K, B]
Partitions this list buffer into a map according to a discriminator function
key
.Partitions this list buffer into a map according to a discriminator function
key
. All the values that have the same discriminator are then transformed by thef
function and then reduced into a single value with thereduce
function.It is equivalent to
groupBy(key).mapValues(_.map(f).reduce(reduce))
, but more efficient.def occurrences[A](as: Seq[A]): Map[A, Int] = as.groupMapReduce(identity)(_ => 1)(_ + _)
Note: Even when applied to a view or a lazy collection it will always force the elements.
- Definition Classes
- IterableOps
- def grouped(size: Int): Iterator[ListBuffer[A]]
Partitions elements in fixed size list buffers.
Partitions elements in fixed size list buffers.
- size
the number of elements per group
- returns
An iterator producing list buffers of size
size
, except the last will be less than sizesize
if the elements don't divide evenly.
- Definition Classes
- IterableOps
- See also
scala.collection.Iterator, method
grouped
- def hashCode(): Int
The hashCode method for reference types.
- def head: A
Selects the first element of this list buffer.
Selects the first element of this list buffer.
- returns
the first element of this list buffer.
- Definition Classes
- IterableOps
- Exceptions thrown
NoSuchElementException
if the list buffer is empty.
- def headOption: Option[A]
Optionally selects the first element.
Optionally selects the first element.
- returns
the first element of this list buffer if it is nonempty,
None
if it is empty.
- Definition Classes
- IterableOps
- def indexOf[B >: A](elem: B): Int
Finds index of first occurrence of some value in this list buffer.
Finds index of first occurrence of some value in this list buffer.
- B
the type of the element
elem
.- elem
the element value to search for.
- returns
the index
>= 0
of the first element of this list buffer that is equal (as determined by==
) toelem
, or-1
, if none exists.
- Definition Classes
- SeqOps
- Annotations
- @deprecatedOverriding()
- def indexOf[B >: A](elem: B, from: Int): Int
Finds index of first occurrence of some value in this list buffer after or at some start index.
Finds index of first occurrence of some value in this list buffer after or at some start index.
- B
the type of the element
elem
.- elem
the element value to search for.
- from
the start index
- returns
the index
>= from
of the first element of this list buffer that is equal (as determined by==
) toelem
, or-1
, if none exists.
- Definition Classes
- SeqOps
- def indexOfSlice[B >: A](that: collection.Seq[B]): Int
Finds first index where this list buffer contains a given sequence as a slice.
Finds first index where this list buffer contains a given sequence as a slice.
- that
the sequence to test
- returns
the first index
>= 0
such that the elements of this list buffer starting at this index match the elements of sequencethat
, or-1
if no such subsequence exists.
- Definition Classes
- SeqOps
- Annotations
- @deprecatedOverriding()
- def indexOfSlice[B >: A](that: collection.Seq[B], from: Int): Int
Finds first index after or at a start index where this list buffer contains a given sequence as a slice.
Finds first index after or at a start index where this list buffer contains a given sequence as a slice.
- that
the sequence to test
- from
the start index
- returns
the first index
>= from
such that the elements of this list buffer starting at this index match the elements of sequencethat
, or-1
if no such subsequence exists.
- Definition Classes
- SeqOps
- def indexWhere(p: (A) => Boolean): Int
Finds index of the first element satisfying some predicate.
Finds index of the first element satisfying some predicate.
- p
the predicate used to test elements.
- returns
the index
>= 0
of the first element of this list buffer that satisfies the predicatep
, or-1
, if none exists.
- Definition Classes
- SeqOps
- Annotations
- @deprecatedOverriding()
- def indexWhere(p: (A) => Boolean, from: Int): Int
Finds index of the first element satisfying some predicate after or at some start index.
Finds index of the first element satisfying some predicate after or at some start index.
- p
the predicate used to test elements.
- from
the start index
- returns
the index
>= from
of the first element of this list buffer that satisfies the predicatep
, or-1
, if none exists.
- Definition Classes
- SeqOps
- def indices: immutable.Range
Produces the range of all indices of this sequence.
Produces the range of all indices of this sequence.
Note: Even when applied to a view or a lazy collection it will always force the elements.
- returns
a
Range
value from0
to one less than the length of this list buffer.
- Definition Classes
- SeqOps
- def init: ListBuffer[A]
The initial part of the collection without its last element.
The initial part of the collection without its last element.
Note: Even when applied to a view or a lazy collection it will always force the elements.
- Definition Classes
- IterableOps
- def inits: Iterator[ListBuffer[A]]
Iterates over the inits of this list buffer.
Iterates over the inits of this list buffer. The first value will be this list buffer and the final one will be an empty list buffer, with the intervening values the results of successive applications of
init
.Note: Even when applied to a view or a lazy collection it will always force the elements.
- returns
an iterator over all the inits of this list buffer
- Definition Classes
- IterableOps
List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)
Example: - def insert(idx: Int, elem: A): Unit
Inserts a new element at a given index into this buffer.
Inserts a new element at a given index into this buffer.
- idx
the index where the new elements is inserted.
- elem
the element to insert.
- Definition Classes
- ListBuffer → Buffer
- Exceptions thrown
IndexOutOfBoundsException
if the indexidx
is not in the valid range0 <= idx <= length
.
- def insertAll(idx: Int, elems: IterableOnce[A]): Unit
Inserts new elements at the index
idx
.Inserts new elements at the index
idx
. Opposed to methodupdate
, this method will not replace an element with a new one. Instead, it will insert a new element at indexidx
.- idx
the index where a new element will be inserted.
- elems
the iterable object providing all elements to insert.
- Definition Classes
- ListBuffer → Buffer
- Exceptions thrown
IndexOutOfBoundsException
ifidx
is out of bounds.
- def intersect[B >: A](that: collection.Seq[B]): ListBuffer[A]
Computes the multiset intersection between this list buffer and another sequence.
Computes the multiset intersection between this list buffer and another sequence.
- that
the sequence of elements to intersect with.
- returns
a new list buffer which contains all elements of this list buffer which also appear in
that
. If an element valuex
appears n times inthat
, then the first n occurrences ofx
will be retained in the result, but any following occurrences will be omitted.
- Definition Classes
- StrictOptimizedSeqOps → SeqOps
- def isDefinedAt(idx: Int): Boolean
Tests whether this list buffer contains given index.
Tests whether this list buffer contains given index.
The implementations of methods
apply
andisDefinedAt
turn aSeq[A]
into aPartialFunction[Int, A]
.- idx
the index to test
- returns
true
if this list buffer contains an element at positionidx
,false
otherwise.
- Definition Classes
- SeqOps
- def isEmpty: Boolean
Tests whether the list buffer is empty.
Tests whether the list buffer is empty.
Note: The default implementation creates and discards an iterator.
Note: Implementations in subclasses that are not repeatedly iterable must take care not to consume any elements when
isEmpty
is called.- returns
true
if the list buffer contains no elements,false
otherwise.
- Definition Classes
- ListBuffer → SeqOps → IterableOnceOps
- final def isInstanceOf[T0]: Boolean
Test whether the dynamic type of the receiver object has the same erasure as
T0
.Test whether the dynamic type of the receiver object has the same erasure as
T0
.Depending on what
T0
is, the test is done in one of the below ways:T0
is a non-parameterized class type, e.g.BigDecimal
: this method returnstrue
if the value of the receiver object is aBigDecimal
or a subtype ofBigDecimal
.T0
is a parameterized class type, e.g.List[Int]
: this method returnstrue
if the value of the receiver object is someList[X]
for anyX
. For example,List(1, 2, 3).isInstanceOf[List[String]]
will return true.T0
is some singleton typex.type
or literalx
: this method returnsthis.eq(x)
. For example,x.isInstanceOf[1]
is equivalent tox.eq(1)
T0
is an intersectionX with Y
orX & Y: this method is equivalent to
x.isInstanceOf[X] && x.isInstanceOf[Y]T0
is a unionX | Y
: this method is equivalent tox.isInstanceOf[X] || x.isInstanceOf[Y]
T0
is a type parameter or an abstract type member: this method is equivalent toisInstanceOf[U]
whereU
isT0
's upper bound,Any
ifT0
is unbounded. For example,x.isInstanceOf[A]
whereA
is an unbounded type parameter will return true for any value ofx
.
This is exactly equivalent to the type pattern
_: T0
- returns
true
if the receiver object is an instance of erasure of typeT0
;false
otherwise.
- Definition Classes
- Any
- Note
due to the unexpectedness of
List(1, 2, 3).isInstanceOf[List[String]]
returning true andx.isInstanceOf[A]
whereA
is a type parameter or abstract member returning true, these forms issue a warning.
- def isTraversableAgain: Boolean
Tests whether this list buffer can be repeatedly traversed.
Tests whether this list buffer can be repeatedly traversed. Always true for Iterables and false for Iterators unless overridden.
- returns
true
if it is repeatedly traversable,false
otherwise.
- Definition Classes
- IterableOps → IterableOnceOps
- def iterableFactory: SeqFactory[ListBuffer]
The companion object of this list buffer, providing various factory methods.
The companion object of this list buffer, providing various factory methods.
- Definition Classes
- ListBuffer → Buffer → Seq → Iterable → Seq → Iterable → IterableOps
- Note
When implementing a custom collection type and refining
CC
to the new type, this method needs to be overridden to return a factory for the new type (the compiler will issue an error otherwise).
- def iterator: Iterator[A]
An scala.collection.Iterator over the elements of this list buffer.
An scala.collection.Iterator over the elements of this list buffer.
If an
IterableOnce
object is in fact an scala.collection.Iterator, this method always returns itself, in its current state, but if it is an scala.collection.Iterable, this method always returns a new scala.collection.Iterator.- Definition Classes
- ListBuffer → IterableOnce
- def knownSize: Int
The number of elements in the collection under construction, if it can be cheaply computed, -1 otherwise.
The number of elements in the collection under construction, if it can be cheaply computed, -1 otherwise.
- returns
The number of elements. The default implementation always returns -1.
- Definition Classes
- ListBuffer → Buffer → Growable → IterableOnce
- def last: A
Selects the last element.
Selects the last element.
Runs in constant time.
- returns
The last element of this list buffer.
- Definition Classes
- ListBuffer → IterableOps
- Exceptions thrown
NoSuchElementException
If the list buffer is empty.
- def lastIndexOf[B >: A](elem: B, end: Int = length - 1): Int
Finds index of last occurrence of some value in this list buffer before or at a given end index.
Finds index of last occurrence of some value in this list buffer before or at a given end index.
- B
the type of the element
elem
.- elem
the element value to search for.
- end
the end index.
- returns
the index
<= end
of the last element of this list buffer that is equal (as determined by==
) toelem
, or-1
, if none exists.
- Definition Classes
- SeqOps
- def lastIndexOfSlice[B >: A](that: collection.Seq[B]): Int
Finds last index where this list buffer contains a given sequence as a slice.
Finds last index where this list buffer contains a given sequence as a slice.
- that
the sequence to test
- returns
the last index such that the elements of this list buffer starting at this index match the elements of sequence
that
, or-1
if no such subsequence exists.
- Definition Classes
- SeqOps
- Annotations
- @deprecatedOverriding()
- def lastIndexOfSlice[B >: A](that: collection.Seq[B], end: Int): Int
Finds last index before or at a given end index where this list buffer contains a given sequence as a slice.
Finds last index before or at a given end index where this list buffer contains a given sequence as a slice.
- that
the sequence to test
- end
the end index
- returns
the last index
<= end
such that the elements of this list buffer starting at this index match the elements of sequencethat
, or-1
if no such subsequence exists.
- Definition Classes
- SeqOps
- def lastIndexWhere(p: (A) => Boolean): Int
Finds index of last element satisfying some predicate.
Finds index of last element satisfying some predicate.
- p
the predicate used to test elements.
- returns
the index of the last element of this list buffer that satisfies the predicate
p
, or-1
, if none exists.
- Definition Classes
- SeqOps
- Annotations
- @deprecatedOverriding()
- def lastIndexWhere(p: (A) => Boolean, end: Int): Int
Finds index of last element satisfying some predicate before or at given end index.
Finds index of last element satisfying some predicate before or at given end index.
- p
the predicate used to test elements.
- returns
the index
<= end
of the last element of this list buffer that satisfies the predicatep
, or-1
, if none exists.
- Definition Classes
- SeqOps
- def lastOption: Option[A]
Optionally selects the last element.
Optionally selects the last element.
Runs in constant time.
- returns
the last element of this list buffer$ if it is nonempty,
None
if it is empty.
- Definition Classes
- ListBuffer → IterableOps
- def lazyZip[B](that: collection.Iterable[B]): LazyZip2[A, B, ListBuffer.this.type]
Analogous to
zip
except that the elements in each collection are not consumed until a strict operation is invoked on the returnedLazyZip2
decorator.Analogous to
zip
except that the elements in each collection are not consumed until a strict operation is invoked on the returnedLazyZip2
decorator.Calls to
lazyZip
can be chained to support higher arities (up to 4) without incurring the expense of constructing and deconstructing intermediary tuples.val xs = List(1, 2, 3) val res = (xs lazyZip xs lazyZip xs lazyZip xs).map((a, b, c, d) => a + b + c + d) // res == List(4, 8, 12)
- B
the type of the second element in each eventual pair
- that
the iterable providing the second element of each eventual pair
- returns
a decorator
LazyZip2
that allows strict operations to be performed on the lazily evaluated pairs or chained calls tolazyZip
. Implicit conversion toIterable[(A, B)]
is also supported.
- Definition Classes
- Iterable
- def length: Int
The length (number of elements) of the list buffer.
The length (number of elements) of the list buffer.
size
is an alias forlength
inSeq
collections.- Definition Classes
- ListBuffer → SeqOps
- def lengthCompare(that: collection.Iterable[_]): Int
Compares the length of this list buffer to the size of another
Iterable
.Compares the length of this list buffer to the size of another
Iterable
.- that
the
Iterable
whose size is compared with this list buffer's length.- returns
A value
x
wherex < 0 if this.length < that.size x == 0 if this.length == that.size x > 0 if this.length > that.size
The method as implemented here does not call
length
orsize
directly; its running time isO(this.length min that.size)
instead ofO(this.length + that.size)
. The method should be overridden if computingsize
is cheap andknownSize
returns-1
.
- Definition Classes
- SeqOps
- def lengthCompare(len: Int): Int
Compares the length of this list buffer to a test value.
Compares the length of this list buffer to a test value.
- len
the test value that gets compared with the length.
- returns
A value
x
wherex < 0 if this.length < len x == 0 if this.length == len x > 0 if this.length > len
The method as implemented here does not call
length
directly; its running time isO(length min len)
instead ofO(length)
. The method should be overridden if computinglength
is cheap andknownSize
returns-1
.
- final def lengthIs: SizeCompareOps
Returns a value class containing operations for comparing the length of this list buffer to a test value.
Returns a value class containing operations for comparing the length of this list buffer to a test value.
These operations are implemented in terms of
lengthCompare(Int)
, and allow the following more readable usages:this.lengthIs < len // this.lengthCompare(len) < 0 this.lengthIs <= len // this.lengthCompare(len) <= 0 this.lengthIs == len // this.lengthCompare(len) == 0 this.lengthIs != len // this.lengthCompare(len) != 0 this.lengthIs >= len // this.lengthCompare(len) >= 0 this.lengthIs > len // this.lengthCompare(len) > 0
- def lift: (Int) => Option[A]
Turns this partial function into a plain function returning an
Option
result.Turns this partial function into a plain function returning an
Option
result.- returns
a function that takes an argument
x
toSome(this(x))
ifthis
is defined forx
, and toNone
otherwise.
- Definition Classes
- PartialFunction
- See also
Function.unlift
- def map[B](f: (A) => B): ListBuffer[B]
Builds a new list buffer by applying a function to all elements of this list buffer.
Builds a new list buffer by applying a function to all elements of this list buffer.
- B
the element type of the returned list buffer.
- f
the function to apply to each element.
- returns
a new list buffer resulting from applying the given function
f
to each element of this list buffer and collecting the results.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def mapInPlace(f: (A) => A): ListBuffer.this.type
Replace the contents of this list buffer with the mapped result.
Replace the contents of this list buffer with the mapped result.
- f
the mapping function
- returns
this list buffer
- def mapResult[NewTo](f: (immutable.List[A]) => NewTo): Builder[A, NewTo]
A builder resulting from this builder my mapping the result using
f
.A builder resulting from this builder my mapping the result using
f
.- Definition Classes
- Builder
- def max[B >: A](implicit ord: math.Ordering[B]): A
Finds the largest element.
Finds the largest element.
- B
The type over which the ordering is defined.
- ord
An ordering to be used for comparing elements.
- returns
the largest element of this list buffer with respect to the ordering
ord
.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this list buffer is empty.
- def maxBy[B](f: (A) => B)(implicit ord: math.Ordering[B]): A
Finds the first element which yields the largest value measured by function
f
.Finds the first element which yields the largest value measured by function
f
.- B
The result type of the function
f
.- f
The measuring function.
- returns
the first element of this list buffer with the largest value measured by function
f
with respect to the orderingcmp
.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this list buffer is empty.
- def maxByOption[B](f: (A) => B)(implicit ord: math.Ordering[B]): Option[A]
Finds the first element which yields the largest value measured by function
f
.Finds the first element which yields the largest value measured by function
f
.- B
The result type of the function
f
.- f
The measuring function.
- returns
an option value containing the first element of this list buffer with the largest value measured by function
f
with respect to the orderingcmp
.
- Definition Classes
- IterableOnceOps
- def maxOption[B >: A](implicit ord: math.Ordering[B]): Option[A]
Finds the largest element.
Finds the largest element.
- B
The type over which the ordering is defined.
- ord
An ordering to be used for comparing elements.
- returns
an option value containing the largest element of this list buffer with respect to the ordering
ord
.
- Definition Classes
- IterableOnceOps
- def min[B >: A](implicit ord: math.Ordering[B]): A
Finds the smallest element.
Finds the smallest element.
- B
The type over which the ordering is defined.
- ord
An ordering to be used for comparing elements.
- returns
the smallest element of this list buffer with respect to the ordering
ord
.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this list buffer is empty.
- def minBy[B](f: (A) => B)(implicit ord: math.Ordering[B]): A
Finds the first element which yields the smallest value measured by function
f
.Finds the first element which yields the smallest value measured by function
f
.- B
The result type of the function
f
.- f
The measuring function.
- returns
the first element of this list buffer with the smallest value measured by function
f
with respect to the orderingcmp
.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this list buffer is empty.
- def minByOption[B](f: (A) => B)(implicit ord: math.Ordering[B]): Option[A]
Finds the first element which yields the smallest value measured by function
f
.Finds the first element which yields the smallest value measured by function
f
.- B
The result type of the function
f
.- f
The measuring function.
- returns
an option value containing the first element of this list buffer with the smallest value measured by function
f
with respect to the orderingcmp
.
- Definition Classes
- IterableOnceOps
- def minOption[B >: A](implicit ord: math.Ordering[B]): Option[A]
Finds the smallest element.
Finds the smallest element.
- B
The type over which the ordering is defined.
- ord
An ordering to be used for comparing elements.
- returns
an option value containing the smallest element of this list buffer with respect to the ordering
ord
.
- Definition Classes
- IterableOnceOps
- final def mkString: String
Displays all elements of this list buffer in a string.
Displays all elements of this list buffer in a string.
Delegates to addString, which can be overridden.
- returns
a string representation of this list buffer. In the resulting string the string representations (w.r.t. the method
toString
) of all elements of this list buffer follow each other without any separator string.
- Definition Classes
- IterableOnceOps
- Annotations
- @inline()
- final def mkString(sep: String): String
Displays all elements of this list buffer in a string using a separator string.
Displays all elements of this list buffer in a string using a separator string.
Delegates to addString, which can be overridden.
- sep
the separator string.
- returns
a string representation of this list buffer. In the resulting string the string representations (w.r.t. the method
toString
) of all elements of this list buffer are separated by the stringsep
.
- Definition Classes
- IterableOnceOps
- Annotations
- @inline()
List(1, 2, 3).mkString("|") = "1|2|3"
Example: - final def mkString(start: String, sep: String, end: String): String
Displays all elements of this list buffer in a string using start, end, and separator strings.
Displays all elements of this list buffer in a string using start, end, and separator strings.
Delegates to addString, which can be overridden.
- start
the starting string.
- sep
the separator string.
- end
the ending string.
- returns
a string representation of this list buffer. The resulting string begins with the string
start
and ends with the stringend
. Inside, the string representations (w.r.t. the methodtoString
) of all elements of this list buffer are separated by the stringsep
.
- Definition Classes
- IterableOnceOps
List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"
Example: - final def ne(arg0: AnyRef): Boolean
Equivalent to
!(this eq that)
.Equivalent to
!(this eq that)
.- returns
true
if the argument is not a reference to the receiver object;false
otherwise.
- Definition Classes
- AnyRef
- def newSpecificBuilder: Builder[A, ListBuffer[A]]
- returns
a strict builder for the same collection type. Note that in the case of lazy collections (e.g. scala.collection.View or scala.collection.immutable.LazyList), it is possible to implement this method but the resulting
Builder
will break laziness. As a consequence, operations should preferably be implemented withfromSpecific
instead of this method.
- Attributes
- protected
- Definition Classes
- IterableFactoryDefaults → IterableOps
- Note
When implementing a custom collection type and refining
,C
to the new type, this method needs to be overridden (the compiler will issue an error otherwise). In the common case whereC =:= CC[A]
, this can be done by mixing in the scala.collection.IterableFactoryDefaults trait, which implements the method using iterableFactory.As witnessed by the
@uncheckedVariance
annotation, using this method might be unsound. However, as long as the returned builder is only fed withA
values taken fromthis
instance, it is safe.
- def nonEmpty: Boolean
Tests whether the list buffer is not empty.
Tests whether the list buffer is not empty.
- returns
true
if the list buffer contains at least one element,false
otherwise.
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecatedOverriding()
- final def notify(): Unit
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up a single thread that is waiting on the receiver object's monitor.
- Definition Classes
- AnyRef
- Annotations
- @native()
- Note
not specified by SLS as a member of AnyRef
- final def notifyAll(): Unit
Wakes up all threads that are waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
- Definition Classes
- AnyRef
- Annotations
- @native()
- Note
not specified by SLS as a member of AnyRef
- def occCounts[B](sq: collection.Seq[B]): Map[B, Int]
- Attributes
- protected[collection]
- Definition Classes
- SeqOps
- def orElse[A1 <: Int, B1 >: A](that: PartialFunction[A1, B1]): PartialFunction[A1, B1]
Composes this partial function with a fallback partial function which gets applied where this partial function is not defined.
Composes this partial function with a fallback partial function which gets applied where this partial function is not defined.
- A1
the argument type of the fallback function
- B1
the result type of the fallback function
- that
the fallback function
- returns
a partial function which has as domain the union of the domains of this partial function and
that
. The resulting partial function takesx
tothis(x)
wherethis
is defined, and tothat(x)
where it is not.
- Definition Classes
- PartialFunction
- def padTo[B >: A](len: Int, elem: B): ListBuffer[B]
A copy of this list buffer with an element value appended until a given target length is reached.
A copy of this list buffer with an element value appended until a given target length is reached.
- B
the element type of the returned list buffer.
- len
the target length
- elem
the padding value
- returns
a new list buffer consisting of all elements of this list buffer followed by the minimal number of occurrences of
elem
so that the resulting collection has a length of at leastlen
.
- Definition Classes
- StrictOptimizedSeqOps → SeqOps
- def padToInPlace(len: Int, elem: A): ListBuffer.this.type
Append the given element to this list buffer until a target length is reached.
Append the given element to this list buffer until a target length is reached.
- len
the target length
- elem
the padding value
- returns
this list buffer
- Definition Classes
- Buffer
- def partition(p: (A) => Boolean): (ListBuffer[A], ListBuffer[A])
A pair of, first, all elements that satisfy predicate
p
and, second, all elements that do not.A pair of, first, all elements that satisfy predicate
p
and, second, all elements that do not.The two list buffer correspond to the result of filter and filterNot, respectively.
The default implementation provided here needs to traverse the collection twice. Strict collections have an overridden version of
partition
inStrictOptimizedIterableOps
, which requires only a single traversal.- Definition Classes
- StrictOptimizedIterableOps → IterableOps
- def partitionMap[A1, A2](f: (A) => Either[A1, A2]): (ListBuffer[A1], ListBuffer[A2])
Applies a function
f
to each element of the list buffer and returns a pair of list buffers: the first one made of those values returned byf
that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.Applies a function
f
to each element of the list buffer and returns a pair of list buffers: the first one made of those values returned byf
that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.Example:
val xs = `ListBuffer`(1, "one", 2, "two", 3, "three") partitionMap { case i: Int => Left(i) case s: String => Right(s) } // xs == (`ListBuffer`(1, 2, 3), // `ListBuffer`(one, two, three))
- A1
the element type of the first resulting collection
- A2
the element type of the second resulting collection
- f
the 'split function' mapping the elements of this list buffer to an scala.util.Either
- returns
a pair of list buffers: the first one made of those values returned by
f
that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps
- def patch[B >: A](from: Int, other: IterableOnce[B], replaced: Int): ListBuffer[B]
Produces a new list buffer where a slice of elements in this list buffer is replaced by another sequence.
Produces a new list buffer where a slice of elements in this list buffer is replaced by another sequence.
Patching at negative indices is the same as patching starting at 0. Patching at indices at or larger than the length of the original list buffer appends the patch to the end. If the
replaced
count would exceed the available elements, the difference in excess is ignored.- B
the element type of the returned list buffer.
- from
the index of the first replaced element
- other
the replacement sequence
- replaced
the number of elements to drop in the original list buffer
- returns
a new list buffer consisting of all elements of this list buffer except that
replaced
elements starting fromfrom
are replaced by all the elements ofother
.
- Definition Classes
- SeqOps
- def patchInPlace(from: Int, patch: IterableOnce[A], replaced: Int): ListBuffer.this.type
Replaces a slice of elements in this list buffer by another sequence of elements.
Replaces a slice of elements in this list buffer by another sequence of elements.
Patching at negative indices is the same as patching starting at 0. Patching at indices at or larger than the length of the original list buffer appends the patch to the end. If the
replaced
count would exceed the available elements, the difference in excess is ignored.- from
the index of the first replaced element
- patch
the replacement sequence
- replaced
the number of elements to drop in the original list buffer
- returns
this list buffer
- Definition Classes
- ListBuffer → Buffer
- def permutations: Iterator[ListBuffer[A]]
Iterates over distinct permutations of elements.
Iterates over distinct permutations of elements.
Note: Even when applied to a view or a lazy collection it will always force the elements.
- returns
An Iterator which traverses the distinct permutations of this list buffer.
- Definition Classes
- SeqOps
Seq('a', 'b', 'b').permutations.foreach(println) // List(a, b, b) // List(b, a, b) // List(b, b, a)
Example: - def prepend(elem: A): ListBuffer.this.type
Prepends a single element at the front of this list buffer.
Prepends a single element at the front of this list buffer.
- elem
the element to add.
- returns
the list buffer itself
- Definition Classes
- ListBuffer → Buffer
- def prependAll(elems: IterableOnce[A]): ListBuffer.this.type
Prepends the elements contained in a iterable object to this buffer.
Prepends the elements contained in a iterable object to this buffer.
- elems
the iterable object containing the elements to append.
- returns
this list buffer
- Definition Classes
- Buffer
- def prependToList(xs: immutable.List[A]): immutable.List[A]
Prepends the elements of this buffer to a given list
Prepends the elements of this buffer to a given list
- xs
the list to which elements are prepended
- def prepended[B >: A](elem: B): ListBuffer[B]
A copy of the list buffer with an element prepended.
A copy of the list buffer with an element prepended.
Also, the original list buffer is not modified, so you will want to capture the result.
Example:
scala> val x = List(1) x: List[Int] = List(1) scala> val y = 2 +: x y: List[Int] = List(2, 1) scala> println(x) List(1)
- B
the element type of the returned list buffer.
- elem
the prepended element
- returns
a new list buffer consisting of
value
followed by all elements of this list buffer.
- Definition Classes
- StrictOptimizedSeqOps → SeqOps
- def prependedAll[B >: A](prefix: IterableOnce[B]): ListBuffer[B]
As with
:++
, returns a new collection containing the elements from the left operand followed by the elements from the right operand.As with
:++
, returns a new collection containing the elements from the left operand followed by the elements from the right operand.It differs from
:++
in that the right operand determines the type of the resulting collection rather than the left one. Mnemonic: the COLon is on the side of the new COLlection type.- B
the element type of the returned collection.
- prefix
the iterable to prepend.
- returns
a new list buffer which contains all elements of
prefix
followed by all the elements of this list buffer.
- Definition Classes
- StrictOptimizedSeqOps → SeqOps
- def product[B >: A](implicit num: math.Numeric[B]): B
Multiplies together the elements of this collection.
Multiplies together the elements of this collection.
The default implementation uses
reduce
for a known non-empty collection,foldLeft
otherwise.- B
the result type of the
*
operator.- num
an implicit parameter defining a set of numeric operations which includes the
*
operator to be used in forming the product.- returns
the product of all elements of this list buffer with respect to the
*
operator innum
.
- Definition Classes
- IterableOnceOps
- def reduce[B >: A](op: (B, B) => B): B
Applies the given binary operator
op
to all elements of this list buffer.Applies the given binary operator
op
to all elements of this list buffer.For each application of the operator, each operand is either an element of this list buffer or another such application of the operator. The order of applications of the operator is unspecified and may be nondeterministic. Each element appears exactly once in the computation.
If this collection is ordered, then for any application of the operator, the element(s) appearing in the left operand will precede those in the right.
Note: might return different results for different runs, unless either of the following conditions is met: (1) the operator is associative, and the underlying collection type is ordered; or (2) the operator is associative and commutative.
- B
The type parameter for the binary operator, a supertype of
A
.- op
A binary operator; must be associative for the result to always be the same across runs.
- returns
The result of applying
op
between all the elements if the list buffer is nonempty.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this list buffer is empty.
- def reduceLeft[B >: A](op: (B, A) => B): B
Applies the given binary operator
op
to all elements of this list buffer, going left to right.Applies the given binary operator
op
to all elements of this list buffer, going left to right."Going left to right" only makes sense if this collection is ordered: then if
x1
,x2
, ...,xn
are the elements of this list buffer, the result isop( op( op( ... op(x1, x2) ... ), xn-1), xn)
.If this collection is not ordered, then for each application of the operator, each right operand is an element. In addition, the leftmost operand is the first element of this list buffer and each other left operand is itself an application of the operator. Each element appears exactly once in the computation.
Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
- B
The result type of the binary operator, a supertype of
A
.- op
A binary operator.
- returns
The result of applying
op
to all elements of this list buffer, going left to right.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this list buffer is empty.
- def reduceLeftOption[B >: A](op: (B, A) => B): Option[B]
If this list buffer is nonempty, reduces it with the given binary operator
op
, going left to right.If this list buffer is nonempty, reduces it with the given binary operator
op
, going left to right.The behavior is the same as reduceLeft except that the value is
None
if the list buffer is empty. Each element appears exactly once in the computation.Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
- B
The result type of the binary operator, a supertype of
A
.- op
A binary operator.
- returns
The result of reducing this list buffer with
op
going left to right if the list buffer is nonempty, inside aSome
, andNone
otherwise.
- Definition Classes
- IterableOnceOps
- def reduceOption[B >: A](op: (B, B) => B): Option[B]
If this list buffer is nonempty, reduces it with the given binary operator
op
.If this list buffer is nonempty, reduces it with the given binary operator
op
.The behavior is the same as reduce except that the value is
None
if the list buffer is empty. The order of applications of the operator is unspecified and may be nondeterministic. Each element appears exactly once in the computation.Note: might return different results for different runs, unless either of the following conditions is met: (1) the operator is associative, and the underlying collection type is ordered; or (2) the operator is associative and commutative.
- B
A type parameter for the binary operator, a supertype of
A
.- op
A binary operator; must be associative for the result to always be the same across runs.
- returns
The result of reducing this list buffer with
op
if the list buffer is nonempty, inside aSome
, andNone
otherwise.
- Definition Classes
- IterableOnceOps
- def reduceRight[B >: A](op: (A, B) => B): B
Applies the given binary operator
op
to all elements of this list buffer, going right to left.Applies the given binary operator
op
to all elements of this list buffer, going right to left."Going right to left" only makes sense if this collection is ordered: then if
x1
,x2
, ...,xn
are the elements of this list buffer, the result isop(x1, op(x2, op( ... op(xn-1, xn) ... )))
.If this collection is not ordered, then for each application of the operator, each left operand is an element. In addition, the rightmost operand is the last element of this list buffer and each other right operand is itself an application of the operator. Each element appears exactly once in the computation.
Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
- B
The result type of the binary operator, a supertype of
A
.- op
A binary operator.
- returns
The result of applying
op
to all elements of this list buffer, going right to left.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this list buffer is empty.
- def reduceRightOption[B >: A](op: (A, B) => B): Option[B]
If this list buffer is nonempty, reduces it with the given binary operator
op
, going right to left.If this list buffer is nonempty, reduces it with the given binary operator
op
, going right to left.The behavior is the same as reduceRight except that the value is
None
if the list buffer is empty. Each element appears exactly once in the computation.Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
- B
The result type of the binary operator, a supertype of
A
.- op
A binary operator.
- returns
The result of reducing this list buffer with
op
going right to left if the list buffer is nonempty, inside aSome
, andNone
otherwise.
- Definition Classes
- IterableOnceOps
- def remove(idx: Int, count: Int): Unit
Removes the element on a given index position.
Removes the element on a given index position. It takes time linear in the buffer size.
- idx
the index which refers to the first element to remove.
- count
the number of elements to remove.
- Definition Classes
- ListBuffer → Buffer
- Exceptions thrown
IllegalArgumentException
ifcount < 0
.IndexOutOfBoundsException
if the indexidx
is not in the valid range0 <= idx <= length - count
(withcount > 0
).
- def remove(idx: Int): A
Removes the element at a given index position.
Removes the element at a given index position.
- idx
the index which refers to the element to delete.
- returns
the element that was formerly at index
idx
.
- Definition Classes
- ListBuffer → Buffer
- def result(): immutable.List[A]
Produces a collection from the added elements.
Produces a collection from the added elements.
After a call to
result
, the behavior of all other methods is undefined save forclear()
. Ifclear()
is called, then the builder is reset and may be used to build another instance.- returns
a collection containing the elements added to this builder.
- Definition Classes
- ListBuffer → ReusableBuilder → Builder
- def reverse: ListBuffer[A]
Returns a new list buffer with the elements of this list buffer in reverse order.
Returns a new list buffer with the elements of this list buffer in reverse order.
Note: Even when applied to a view or a lazy collection it will always force the elements.
- returns
a new list buffer with all elements of this list buffer in reverse order.
- Definition Classes
- SeqOps
- def reverseIterator: Iterator[A]
An iterator yielding the elements of this list buffer in reverse order.
An iterator yielding the elements of this list buffer in reverse order.
Note:
xs.reverseIterator
is the same asxs.reverse.iterator
but might be more efficient.- returns
an iterator yielding the elements of this list buffer in reverse order.
- Definition Classes
- SeqOps
- def reversed: collection.Iterable[A]
- Attributes
- protected
- Definition Classes
- IterableOnceOps
- def runWith[U](action: (A) => U): (Int) => Boolean
Composes this partial function with an action function which gets applied to results of this partial function.
Composes this partial function with an action function which gets applied to results of this partial function. The action function is invoked only for its side effects; its result is ignored.
Note that expression
pf.runWith(action)(x)
is equivalent toif(pf isDefinedAt x) { action(pf(x)); true } else false
except that
runWith
is implemented viaapplyOrElse
and thus potentially more efficient. UsingrunWith
avoids double evaluation of pattern matchers and guards for partial function literals.- action
the action function
- returns
a function which maps arguments
x
toisDefinedAt(x)
. The resulting function runsaction(this(x))
wherethis
is defined.
- Definition Classes
- PartialFunction
- See also
applyOrElse
.
- def sameElements[B >: A](that: IterableOnce[B]): Boolean
Tests whether the elements of this collection are the same (and in the same order) as those of
that
.Tests whether the elements of this collection are the same (and in the same order) as those of
that
.- Definition Classes
- SeqOps
- def scan[B >: A](z: B)(op: (B, B) => B): ListBuffer[B]
Computes a prefix scan of the elements of the collection.
Computes a prefix scan of the elements of the collection.
Note: The neutral element
z
may be applied more than once.- B
element type of the resulting collection
- z
neutral element for the operator
op
- op
the associative operator for the scan
- returns
a new list buffer containing the prefix scan of the elements in this list buffer
- Definition Classes
- IterableOps
- def scanLeft[B](z: B)(op: (B, A) => B): ListBuffer[B]
Produces a list buffer containing cumulative results of applying the operator going left to right, including the initial value.
Produces a list buffer containing cumulative results of applying the operator going left to right, including the initial value.
- B
the type of the elements in the resulting collection
- z
the initial value
- op
the binary operator applied to the intermediate result and the element
- returns
collection with intermediate results
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def scanRight[B](z: B)(op: (A, B) => B): ListBuffer[B]
Produces a collection containing cumulative results of applying the operator going right to left.
Produces a collection containing cumulative results of applying the operator going right to left. The head of the collection is the last cumulative result.
Note: Even when applied to a view or a lazy collection it will always force the elements.
Example:
List(1, 2, 3, 4).scanRight(0)(_ + _) == List(10, 9, 7, 4, 0)
- B
the type of the elements in the resulting collection
- z
the initial value
- op
the binary operator applied to the intermediate result and the element
- returns
collection with intermediate results
- Definition Classes
- IterableOps
- def search[B >: A](elem: B, from: Int, to: Int)(implicit ord: Ordering[B]): SearchResult
Searches within an interval in this sorted sequence for a specific element.
Searches within an interval in this sorted sequence for a specific element. If this sequence is an
IndexedSeq
, a binary search is used. Otherwise, a linear search is used.The sequence should be sorted with the same
Ordering
before calling; otherwise, the results are undefined.- elem
the element to find.
- from
the index where the search starts.
- to
the index following where the search ends.
- ord
the ordering to be used to compare elements.
- returns
a
Found
value containing the index corresponding to the element in the sequence, or theInsertionPoint
where the element would be inserted if the element is not in the sequence.
- Definition Classes
- SeqOps
- Note
if
to <= from
, the search space is empty, and anInsertionPoint
atfrom
is returned- See also
scala.collection.SeqOps, method
sorted
- def search[B >: A](elem: B)(implicit ord: Ordering[B]): SearchResult
Searches this sorted sequence for a specific element.
Searches this sorted sequence for a specific element. If the sequence is an
IndexedSeq
, a binary search is used. Otherwise, a linear search is used.The sequence should be sorted with the same
Ordering
before calling; otherwise, the results are undefined.- elem
the element to find.
- ord
the ordering to be used to compare elements.
- returns
a
Found
value containing the index corresponding to the element in the sequence, or theInsertionPoint
where the element would be inserted if the element is not in the sequence.
- Definition Classes
- SeqOps
- See also
scala.collection.SeqOps, method
sorted
- def segmentLength(p: (A) => Boolean, from: Int): Int
Computes the length of the longest segment that starts from some index and whose elements all satisfy some predicate.
Computes the length of the longest segment that starts from some index and whose elements all satisfy some predicate.
- p
the predicate used to test elements.
- from
the index where the search starts.
- returns
the length of the longest segment of this list buffer starting from index
from
such that every element of the segment satisfies the predicatep
.
- Definition Classes
- SeqOps
- final def segmentLength(p: (A) => Boolean): Int
Computes the length of the longest segment that starts from the first element and whose elements all satisfy some predicate.
Computes the length of the longest segment that starts from the first element and whose elements all satisfy some predicate.
- p
the predicate used to test elements.
- returns
the length of the longest segment of this list buffer that starts from the first element such that every element of the segment satisfies the predicate
p
.
- Definition Classes
- SeqOps
- final def size: Int
The size of this list buffer.
The size of this list buffer.
- returns
the number of elements in this list buffer.
- Definition Classes
- SeqOps → IterableOnceOps
- final def sizeCompare(that: collection.Iterable[_]): Int
Compares the size of this list buffer to the size of another
Iterable
.Compares the size of this list buffer to the size of another
Iterable
.- that
the
Iterable
whose size is compared with this list buffer's size.- returns
A value
x
wherex < 0 if this.size < that.size x == 0 if this.size == that.size x > 0 if this.size > that.size
The method as implemented here does not call
size
directly; its running time isO(this.size min that.size)
instead ofO(this.size + that.size)
. The method should be overridden if computingsize
is cheap andknownSize
returns-1
.
- Definition Classes
- SeqOps → IterableOps
- final def sizeCompare(otherSize: Int): Int
Compares the size of this list buffer to a test value.
Compares the size of this list buffer to a test value.
- otherSize
the test value that gets compared with the size.
- returns
A value
x
wherex < 0 if this.size < otherSize x == 0 if this.size == otherSize x > 0 if this.size > otherSize
The method as implemented here does not call
size
directly; its running time isO(size min otherSize)
instead ofO(size)
. The method should be overridden if computingsize
is cheap andknownSize
returns-1
.
- Definition Classes
- SeqOps → IterableOps
- See also
- final def sizeHint(coll: IterableOnce[_], delta: Int = 0): Unit
Gives a hint that the
result
of this builder is expected to have the same size as the given collection, plus some delta.Gives a hint that the
result
of this builder is expected to have the same size as the given collection, plus some delta.This method provides a hint only if the collection has a known size, as specified by the following pseudocode:
if (coll.knownSize != -1) if (coll.knownSize + delta <= 0) sizeHint(0) else sizeHint(coll.knownSize + delta)
If the delta is negative and the result size is known to be negative, then the size hint is issued at zero.
Some builder classes will optimize their representation based on the hint. However, builder implementations are required to work correctly even if the hint is wrong, i.e., if a different number of elements is added.
- coll
the collection which serves as a hint for the result's size.
- delta
a correction to add to the
coll.size
to produce the size hint (zero if omitted).
- Definition Classes
- Builder
- def sizeHint(size: Int): Unit
Gives a hint how many elements are expected to be added in total by the time
result
is called.Gives a hint how many elements are expected to be added in total by the time
result
is called.Some builder classes will optimize their representation based on the hint. However, builder implementations are required to work correctly even if the hint is wrong, e.g., a different number of elements is added, or the hint is out of range.
The default implementation simply ignores the hint.
- size
the hint how many elements will be added.
- Definition Classes
- Builder
- final def sizeHintBounded(size: Int, boundingColl: collection.Iterable[_]): Unit
Gives a hint how many elements are expected to be added when the next
result
is called, together with an upper bound given by the size of some other collection.Gives a hint how many elements are expected to be added when the next
result
is called, together with an upper bound given by the size of some other collection. Some builder classes will optimize their representation based on the hint. However, builder implementations are still required to work correctly even if the hint is wrong, i.e. a different number of elements is added.- size
the hint how many elements will be added.
- boundingColl
the bounding collection. If it is an IndexedSeqLike, then sizes larger than collection's size are reduced.
- Definition Classes
- Builder
- final def sizeIs: SizeCompareOps
Returns a value class containing operations for comparing the size of this list buffer to a test value.
Returns a value class containing operations for comparing the size of this list buffer to a test value.
These operations are implemented in terms of
sizeCompare(Int)
, and allow the following more readable usages:this.sizeIs < size // this.sizeCompare(size) < 0 this.sizeIs <= size // this.sizeCompare(size) <= 0 this.sizeIs == size // this.sizeCompare(size) == 0 this.sizeIs != size // this.sizeCompare(size) != 0 this.sizeIs >= size // this.sizeCompare(size) >= 0 this.sizeIs > size // this.sizeCompare(size) > 0
- Definition Classes
- IterableOps
- Annotations
- @inline()
- def slice(from: Int, until: Int): ListBuffer[A]
Selects an interval of elements.
Selects an interval of elements. The returned list buffer is made up of all elements
x
which satisfy the invariant:from <= indexOf(x) < until
- from
the lowest index to include from this list buffer.
- until
the lowest index to EXCLUDE from this list buffer.
- returns
a list buffer containing the elements greater than or equal to index
from
extending up to (but not including) indexuntil
of this list buffer.
- Definition Classes
- IterableOps → IterableOnceOps
- def sliceInPlace(start: Int, end: Int): ListBuffer.this.type
Retains the specified slice from this list buffer and removes the rest.
Retains the specified slice from this list buffer and removes the rest.
- start
the lowest index to include
- end
the lowest index to exclude
- returns
this list buffer
- Definition Classes
- Buffer
- def sliding(size: Int, step: Int): Iterator[ListBuffer[A]]
Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in
grouped
).Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in
grouped
).The returned iterator will be empty when called on an empty collection. The last element the iterator produces may be smaller than the window size when the original collection isn't exhausted by the window before it and its last element isn't skipped by the step before it.
- size
the number of elements per group
- step
the distance between the first elements of successive groups
- returns
An iterator producing list buffers of size
size
, except the last element (which may be the only element) will be smaller if there are fewer thansize
elements remaining to be grouped.
- Definition Classes
- IterableOps
List(1, 2, 3, 4, 5).sliding(2, 2) = Iterator(List(1, 2), List(3, 4), List(5))
, List(1, 2, 3, 4, 5, 6).sliding(2, 3) = Iterator(List(1, 2), List(4, 5))
- See also
scala.collection.Iterator, method
sliding
Examples: - def sliding(size: Int): Iterator[ListBuffer[A]]
Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in
grouped
).Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in
grouped
).An empty collection returns an empty iterator, and a non-empty collection containing fewer elements than the window size returns an iterator that will produce the original collection as its only element.
- size
the number of elements per group
- returns
An iterator producing list buffers of size
size
, except for a non-empty collection with less thansize
elements, which returns an iterator that produces the source collection itself as its only element.
- Definition Classes
- IterableOps
List().sliding(2) = empty iterator
, List(1).sliding(2) = Iterator(List(1))
, List(1, 2).sliding(2) = Iterator(List(1, 2))
, List(1, 2, 3).sliding(2) = Iterator(List(1, 2), List(2, 3))
- See also
scala.collection.Iterator, method
sliding
Examples: - def sortBy[B](f: (A) => B)(implicit ord: Ordering[B]): ListBuffer[A]
Sorts this list buffer according to the Ordering which results from transforming an implicitly given Ordering with a transformation function.
Sorts this list buffer according to the Ordering which results from transforming an implicitly given Ordering with a transformation function.
Note: Even when applied to a view or a lazy collection it will always force the elements.
The sort is stable. That is, elements that are equal (as determined by
ord.compare
) appear in the same order in the sorted sequence as in the original.- B
the target type of the transformation
f
, and the type where the orderingord
is defined.- f
the transformation function mapping elements to some other domain
B
.- ord
the ordering assumed on domain
B
.- returns
a list buffer consisting of the elements of this list buffer sorted according to the ordering where
x < y
iford.lt(f(x), f(y))
.
- Definition Classes
- SeqOps
val words = "The quick brown fox jumped over the lazy dog".split(' ') // this works because scala.Ordering will implicitly provide an Ordering[Tuple2[Int, Char]] words.sortBy(x => (x.length, x.head)) res0: Array[String] = Array(The, dog, fox, the, lazy, over, brown, quick, jumped)
- See also
Example: - def sortWith(lt: (A, A) => Boolean): ListBuffer[A]
Sorts this list buffer according to a comparison function.
Sorts this list buffer according to a comparison function.
Note: Even when applied to a view or a lazy collection it will always force the elements.
The sort is stable. That is, elements that are equal (
lt
returns false for both directions of comparison) appear in the same order in the sorted sequence as in the original.- lt
a predicate that is true if its first argument strictly precedes its second argument in the desired ordering.
- returns
a list buffer consisting of the elements of this list buffer sorted according to the comparison function
lt
.
- Definition Classes
- SeqOps
List("Steve", "Bobby", "Tom", "John", "Bob").sortWith((x, y) => x.take(3).compareTo(y.take(3)) < 0) = List("Bobby", "Bob", "John", "Steve", "Tom")
Example: - def sorted[B >: A](implicit ord: Ordering[B]): ListBuffer[A]
Sorts this list buffer according to an Ordering.
Sorts this list buffer according to an Ordering.
The sort is stable. That is, elements that are equal (as determined by
ord.compare
) appear in the same order in the sorted sequence as in the original.- ord
the ordering to be used to compare elements.
- returns
a list buffer consisting of the elements of this list buffer sorted according to the ordering
ord
.
- Definition Classes
- SeqOps
- See also
scala.math.Ordering Note: Even when applied to a view or a lazy collection it will always force the elements.
- def span(p: (A) => Boolean): (ListBuffer[A], ListBuffer[A])
Splits this list buffer into a prefix/suffix pair according to a predicate.
Splits this list buffer into a prefix/suffix pair according to a predicate.
Note:
c span p
is equivalent to (but possibly more efficient than)(c takeWhile p, c dropWhile p)
, provided the evaluation of the predicatep
does not cause any side-effects.- p
the test predicate
- returns
a pair consisting of the longest prefix of this list buffer whose elements all satisfy
p
, and the rest of this list buffer.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def splitAt(n: Int): (ListBuffer[A], ListBuffer[A])
Splits this list buffer into a prefix/suffix pair at a given position.
Splits this list buffer into a prefix/suffix pair at a given position.
Note:
c splitAt n
is equivalent to (but possibly more efficient than)(c take n, c drop n)
.- n
the position at which to split.
- returns
a pair of list buffers consisting of the first
n
elements of this list buffer, and the other elements.
- Definition Classes
- IterableOps → IterableOnceOps
- def startsWith[B >: A](that: IterableOnce[B], offset: Int = 0): Boolean
Tests whether this list buffer contains the given sequence at a given index.
Tests whether this list buffer contains the given sequence at a given index.
Note: If the both the receiver object
this
and the argumentthat
are infinite sequences this method may not terminate.- that
the sequence to test
- offset
the index where the sequence is searched.
- returns
true
if the sequencethat
is contained in this list buffer at indexoffset
, otherwisefalse
.
- Definition Classes
- SeqOps
- def stepper[S <: Stepper[_]](implicit shape: StepperShape[A, S]): S
Returns a scala.collection.Stepper for the elements of this collection.
Returns a scala.collection.Stepper for the elements of this collection.
The Stepper enables creating a Java stream to operate on the collection, see scala.jdk.StreamConverters. For collections holding primitive values, the Stepper can be used as an iterator which doesn't box the elements.
The implicit scala.collection.StepperShape parameter defines the resulting Stepper type according to the element type of this collection.
- For collections of
Int
,Short
,Byte
orChar
, an scala.collection.IntStepper is returned - For collections of
Double
orFloat
, a scala.collection.DoubleStepper is returned - For collections of
Long
a scala.collection.LongStepper is returned - For any other element type, an scala.collection.AnyStepper is returned
Note that this method is overridden in subclasses and the return type is refined to
S with EfficientSplit
, for example scala.collection.IndexedSeqOps.stepper. For Steppers marked with scala.collection.Stepper.EfficientSplit, the converters in scala.jdk.StreamConverters allow creating parallel streams, whereas bare Steppers can be converted only to sequential streams.- Definition Classes
- IterableOnce
- For collections of
- final def strictOptimizedCollect[B, C2](b: Builder[B, C2], pf: PartialFunction[A, B]): C2
- B
Type of elements of the resulting collection (e.g.
String
)- C2
Type of the resulting collection (e.g.
List[String]
)- b
Builder to use to build the resulting collection
- pf
Element transformation partial function
- returns
The resulting collection
- Attributes
- protected[this]
- Definition Classes
- StrictOptimizedIterableOps
- Annotations
- @inline()
- final def strictOptimizedConcat[B >: A, C2](that: IterableOnce[B], b: Builder[B, C2]): C2
- B
Type of elements of the resulting collections (e.g.
Int
)- C2
Type of the resulting collection (e.g.
List[Int]
)- that
Elements to concatenate to this collection
- b
Builder to use to build the resulting collection
- returns
The resulting collection
- Attributes
- protected[this]
- Definition Classes
- StrictOptimizedIterableOps
- Annotations
- @inline()
- final def strictOptimizedFlatMap[B, C2](b: Builder[B, C2], f: (A) => IterableOnce[B]): C2
- B
Type of elements of the resulting collection (e.g.
String
)- C2
Type of the resulting collection (e.g.
List[String]
)- b
Builder to use to build the resulting collection
- f
Element transformation function
- returns
The resulting collection
- Attributes
- protected[this]
- Definition Classes
- StrictOptimizedIterableOps
- Annotations
- @inline()
- final def strictOptimizedFlatten[B, C2](b: Builder[B, C2])(implicit toIterableOnce: (A) => IterableOnce[B]): C2
- B
Type of elements of the resulting collection (e.g.
Int
)- C2
Type of the resulting collection (e.g.
List[Int]
)- b
Builder to use to build the resulting collection
- toIterableOnce
Evidence that
A
can be seen as anIterableOnce[B]
- returns
The resulting collection
- Attributes
- protected[this]
- Definition Classes
- StrictOptimizedIterableOps
- Annotations
- @inline()
- final def strictOptimizedMap[B, C2](b: Builder[B, C2], f: (A) => B): C2
- B
Type of elements of the resulting collection (e.g.
String
)- C2
Type of the resulting collection (e.g.
List[String]
)- b
Builder to use to build the resulting collection
- f
Element transformation function
- returns
The resulting collection
- Attributes
- protected[this]
- Definition Classes
- StrictOptimizedIterableOps
- Annotations
- @inline()
- final def strictOptimizedZip[B, C2](that: IterableOnce[B], b: Builder[(A, B), C2]): C2
- B
Type of elements of the second collection (e.g.
String
)- C2
Type of the resulting collection (e.g.
List[(Int, String)]
)- that
Collection to zip with this collection
- b
Builder to use to build the resulting collection
- returns
The resulting collection
- Attributes
- protected[this]
- Definition Classes
- StrictOptimizedIterableOps
- Annotations
- @inline()
- def stringPrefix: String
- Attributes
- protected[this]
- Definition Classes
- ListBuffer → Buffer → Seq → Iterable
- Annotations
- @nowarn()
- def subtractAll(xs: IterableOnce[A]): ListBuffer.this.type
Removes all elements produced by an iterator from this list buffer.
Removes all elements produced by an iterator from this list buffer.
- xs
the iterator producing the elements to remove.
- returns
the list buffer itself
- Definition Classes
- Shrinkable
- def subtractOne(elem: A): ListBuffer.this.type
Removes a single element from this buffer, at its first occurrence.
Removes a single element from this buffer, at its first occurrence. If the buffer does not contain that element, it is unchanged.
- returns
the buffer itself
- Definition Classes
- ListBuffer → Buffer → Shrinkable
- def sum[B >: A](implicit num: math.Numeric[B]): B
Sums the elements of this collection.
Sums the elements of this collection.
The default implementation uses
reduce
for a known non-empty collection,foldLeft
otherwise.- B
the result type of the
+
operator.- num
an implicit parameter defining a set of numeric operations which includes the
+
operator to be used in forming the sum.- returns
the sum of all elements of this list buffer with respect to the
+
operator innum
.
- Definition Classes
- IterableOnceOps
- final def synchronized[T0](arg0: => T0): T0
Executes the code in
body
with an exclusive lock onthis
.Executes the code in
body
with an exclusive lock onthis
.- returns
the result of
body
- Definition Classes
- AnyRef
- def tail: ListBuffer[A]
The rest of the collection without its first element.
The rest of the collection without its first element.
- Definition Classes
- IterableOps
- def tails: Iterator[ListBuffer[A]]
Iterates over the tails of this list buffer.
Iterates over the tails of this list buffer. The first value will be this list buffer and the final one will be an empty list buffer, with the intervening values the results of successive applications of
tail
.- returns
an iterator over all the tails of this list buffer
- Definition Classes
- IterableOps
List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)
Example: - def take(n: Int): ListBuffer[A]
Selects the first
n
elements.Selects the first
n
elements.- n
the number of elements to take from this list buffer.
- returns
a list buffer consisting only of the first
n
elements of this list buffer, or else the whole list buffer, if it has less thann
elements. Ifn
is negative, returns an empty list buffer.
- Definition Classes
- IterableOps → IterableOnceOps
- def takeInPlace(n: Int): ListBuffer.this.type
Retains the first
n
elements from this list buffer and removes the rest.Retains the first
n
elements from this list buffer and removes the rest.- n
the number of elements to retain
- returns
this list buffer
- Definition Classes
- Buffer
- def takeRight(n: Int): ListBuffer[A]
A collection containing the last
n
elements of this collection.A collection containing the last
n
elements of this collection.Note: Even when applied to a view or a lazy collection it will always force the elements.
- n
the number of elements to take from this list buffer.
- returns
a list buffer consisting only of the last
n
elements of this list buffer, or else the whole list buffer, if it has less thann
elements. Ifn
is negative, returns an empty list buffer.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps
- def takeRightInPlace(n: Int): ListBuffer.this.type
Retains the last
n
elements from this list buffer and removes the rest.Retains the last
n
elements from this list buffer and removes the rest.- n
the number of elements to retain
- returns
this list buffer
- Definition Classes
- Buffer
- def takeWhile(p: (A) => Boolean): ListBuffer[A]
Takes longest prefix of elements that satisfy a predicate.
Takes longest prefix of elements that satisfy a predicate.
- p
The predicate used to test elements.
- returns
the longest prefix of this list buffer whose elements all satisfy the predicate
p
.
- Definition Classes
- IterableOps → IterableOnceOps
- def takeWhileInPlace(p: (A) => Boolean): ListBuffer.this.type
Retains the longest prefix of elements that satisfy a predicate.
- def tapEach[U](f: (A) => U): ListBuffer[A]
Applies a side-effecting function to each element in this collection.
Applies a side-effecting function to each element in this collection. Strict collections will apply
f
to their elements immediately, while lazy collections like Views and LazyLists will only applyf
on each element if and when that element is evaluated, and each time that element is evaluated.- U
the return type of f
- f
a function to apply to each element in this list buffer
- returns
The same logical collection as this
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def to[C1](factory: Factory[A, C1]): C1
Given a collection factory
factory
, converts this list buffer to the appropriate representation for the current element typeA
.Given a collection factory
factory
, converts this list buffer to the appropriate representation for the current element typeA
. Example uses:xs.to(List) xs.to(ArrayBuffer) xs.to(BitSet) // for xs: Iterable[Int]
- Definition Classes
- IterableOnceOps
- def toArray[B >: A](implicit arg0: ClassTag[B]): Array[B]
Converts this list buffer to an
Array
.Converts this list buffer to an
Array
.Implementation note: DO NOT call Array.from from this method.
- B
The type of elements of the result, a supertype of
A
.- returns
This list buffer as an
Array[B]
.
- Definition Classes
- IterableOnceOps
- final def toBuffer[B >: A]: Buffer[B]
Converts this list buffer to a
Buffer
.Converts this list buffer to a
Buffer
.- B
The type of elements of the result, a supertype of
A
.- returns
This list buffer as a
Buffer[B]
.
- Definition Classes
- IterableOnceOps
- Annotations
- @inline()
- def toIndexedSeq: immutable.IndexedSeq[A]
Converts this list buffer to an
IndexedSeq
.Converts this list buffer to an
IndexedSeq
.- returns
This list buffer as an
IndexedSeq[A]
.
- Definition Classes
- IterableOnceOps
- def toList: immutable.List[A]
Converts this list buffer to a
List
.Converts this list buffer to a
List
.- returns
This list buffer as a
List[A]
.
- Definition Classes
- ListBuffer → IterableOnceOps
- def toMap[K, V](implicit ev: <:<[A, (K, V)]): immutable.Map[K, V]
Converts this list buffer to a
Map
, given an implicit coercion from the list buffer's type to a key-value tuple.Converts this list buffer to a
Map
, given an implicit coercion from the list buffer's type to a key-value tuple.- K
The key type for the resulting map.
- V
The value type for the resulting map.
- ev
An implicit coercion from
A
to[K, V]
.- returns
This list buffer as a
Map[K, V]
.
- Definition Classes
- IterableOnceOps
- def toSeq: immutable.Seq[A]
- returns
This list buffer as a
Seq[A]
. This is equivalent toto(Seq)
but might be faster.
- Definition Classes
- IterableOnceOps
- def toSet[B >: A]: immutable.Set[B]
Converts this list buffer to a
Set
.Converts this list buffer to a
Set
.- B
The type of elements of the result, a supertype of
A
.- returns
This list buffer as a
Set[B]
.
- Definition Classes
- IterableOnceOps
- def toString(): String
Creates a String representation of this object.
Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.
- returns
a String representation of the object.
- def toVector: immutable.Vector[A]
Converts this list buffer to a
Vector
.Converts this list buffer to a
Vector
.- returns
This list buffer as a
Vector[A]
.
- Definition Classes
- IterableOnceOps
- def transpose[B](implicit asIterable: (A) => collection.Iterable[B]): ListBuffer[ListBuffer[B]]
Transposes this list buffer of iterable collections into a list buffer of list buffers.
Transposes this list buffer of iterable collections into a list buffer of list buffers.
The resulting collection's type will be guided by the static type of list buffer. For example:
val xs = List( Set(1, 2, 3), Set(4, 5, 6)).transpose // xs == List( // List(1, 4), // List(2, 5), // List(3, 6)) val ys = Vector( List(1, 2, 3), List(4, 5, 6)).transpose // ys == Vector( // Vector(1, 4), // Vector(2, 5), // Vector(3, 6))
Note: Even when applied to a view or a lazy collection it will always force the elements.
- B
the type of the elements of each iterable collection.
- asIterable
an implicit conversion which asserts that the element type of this list buffer is an
Iterable
.- returns
a two-dimensional list buffer of list buffers which has as nth row the nth column of this list buffer.
- Definition Classes
- IterableOps
- Exceptions thrown
IllegalArgumentException
if all collections in this list buffer are not of the same size.
- def unapply(a: Int): Option[A]
Tries to extract a
B
from anA
in a pattern matching expression.Tries to extract a
B
from anA
in a pattern matching expression.- Definition Classes
- PartialFunction
- def unlift: PartialFunction[Int, B]
Converts an optional function to a partial function.
Converts an optional function to a partial function.
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toUnliftOps[Int, B] performed by method UnliftOps in scala.Function1.This conversion will take place only if A is a subclass of Option[B] (A <: Option[B]).
- Definition Classes
- UnliftOps
Unlike Function.unlift, this UnliftOps.unlift method can be used in extractors.
val of: Int => Option[String] = { i => if (i == 2) { Some("matched by an optional function") } else { None } } util.Random.nextInt(4) match { case of.unlift(m) => // Convert an optional function to a pattern println(m) case _ => println("Not matched") }
Example: - def unzip[A1, A2](implicit asPair: (A) => (A1, A2)): (ListBuffer[A1], ListBuffer[A2])
Converts this list buffer of pairs into two collections of the first and second half of each pair.
Converts this list buffer of pairs into two collections of the first and second half of each pair.
val xs = `ListBuffer`( (1, "one"), (2, "two"), (3, "three")).unzip // xs == (`ListBuffer`(1, 2, 3), // `ListBuffer`(one, two, three))
- A1
the type of the first half of the element pairs
- A2
the type of the second half of the element pairs
- asPair
an implicit conversion which asserts that the element type of this list buffer is a pair.
- returns
a pair of list buffers, containing the first, respectively second half of each element pair of this list buffer.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps
- def unzip3[A1, A2, A3](implicit asTriple: (A) => (A1, A2, A3)): (ListBuffer[A1], ListBuffer[A2], ListBuffer[A3])
Converts this list buffer of triples into three collections of the first, second, and third element of each triple.
Converts this list buffer of triples into three collections of the first, second, and third element of each triple.
val xs = `ListBuffer`( (1, "one", '1'), (2, "two", '2'), (3, "three", '3')).unzip3 // xs == (`ListBuffer`(1, 2, 3), // `ListBuffer`(one, two, three), // `ListBuffer`(1, 2, 3))
- A1
the type of the first member of the element triples
- A2
the type of the second member of the element triples
- A3
the type of the third member of the element triples
- asTriple
an implicit conversion which asserts that the element type of this list buffer is a triple.
- returns
a triple of list buffers, containing the first, second, respectively third member of each element triple of this list buffer.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps
- def update(idx: Int, elem: A): Unit
Replaces element at given index with a new value.
Replaces element at given index with a new value.
- idx
the index of the element to replace.
- elem
the new value.
- Definition Classes
- ListBuffer → SeqOps
- Exceptions thrown
IndexOutOfBoundsException
if the index is not valid.
- def updated[B >: A](index: Int, elem: B): ListBuffer[B]
A copy of this list buffer with one single replaced element.
A copy of this list buffer with one single replaced element.
- B
the element type of the returned list buffer.
- index
the position of the replacement
- elem
the replacing element
- returns
a new list buffer which is a copy of this list buffer with the element at position
index
replaced byelem
.
- Definition Classes
- SeqOps
- Exceptions thrown
IndexOutOfBoundsException
ifindex
does not satisfy0 <= index < length
. In case of a lazy collection this exception may be thrown at a later time or not at all (if the end of the collection is never evaluated).
- def view: SeqView[A]
A view over the elements of this collection.
A view over the elements of this collection.
- Definition Classes
- SeqOps → IterableOps
- final def wait(): Unit
See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait--.
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- Note
not specified by SLS as a member of AnyRef
- final def wait(arg0: Long, arg1: Int): Unit
See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-int-
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- Note
not specified by SLS as a member of AnyRef
- final def wait(arg0: Long): Unit
See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-.
- def withFilter(p: (A) => Boolean): WithFilter[A, [_]ListBuffer[_]]
Creates a non-strict filter of this list buffer.
Creates a non-strict filter of this list buffer.
Note: the difference between
c filter p
andc withFilter p
is that the former creates a new collection, whereas the latter only restricts the domain of subsequentmap
,flatMap
,foreach
, andwithFilter
operations.- p
the predicate used to test elements.
- returns
an object of class
WithFilter
, which supportsmap
,flatMap
,foreach
, andwithFilter
operations. All these operations apply to those elements of this list buffer which satisfy the predicatep
.
- Definition Classes
- IterableOps
- def writeReplace(): AnyRef
- Attributes
- protected[this]
- Definition Classes
- DefaultSerializable
- def zip[B](that: IterableOnce[B]): ListBuffer[(A, B)]
Returns a list buffer formed from this list buffer and another iterable collection by combining corresponding elements in pairs.
Returns a list buffer formed from this list buffer and another iterable collection by combining corresponding elements in pairs. If one of the two collections is longer than the other, its remaining elements are ignored.
- B
the type of the second half of the returned pairs
- that
The iterable providing the second half of each result pair
- returns
a new list buffer containing pairs consisting of corresponding elements of this list buffer and
that
. The length of the returned collection is the minimum of the lengths of this list buffer andthat
.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps
- def zipAll[A1 >: A, B](that: collection.Iterable[B], thisElem: A1, thatElem: B): ListBuffer[(A1, B)]
Returns a list buffer formed from this list buffer and another iterable collection by combining corresponding elements in pairs.
Returns a list buffer formed from this list buffer and another iterable collection by combining corresponding elements in pairs. If one of the two collections is shorter than the other, placeholder elements are used to extend the shorter collection to the length of the longer.
- that
the iterable providing the second half of each result pair
- thisElem
the element to be used to fill up the result if this list buffer is shorter than
that
.- thatElem
the element to be used to fill up the result if
that
is shorter than this list buffer.- returns
a new collection of type
That
containing pairs consisting of corresponding elements of this list buffer andthat
. The length of the returned collection is the maximum of the lengths of this list buffer andthat
. If this list buffer is shorter thanthat
,thisElem
values are used to pad the result. Ifthat
is shorter than this list buffer,thatElem
values are used to pad the result.
- Definition Classes
- IterableOps
- def zipWithIndex: ListBuffer[(A, Int)]
Zips this list buffer with its indices.
Zips this list buffer with its indices.
- returns
A new list buffer containing pairs consisting of all elements of this list buffer paired with their index. Indices start at
0
.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
List("a", "b", "c").zipWithIndex == List(("a", 0), ("b", 1), ("c", 2))
Example:
Deprecated Value Members
- final def +=(elem1: A, elem2: A, elems: A*): ListBuffer.this.type
Adds two or more elements to this list buffer.
Adds two or more elements to this list buffer.
- elem1
the first element to add.
- elem2
the second element to add.
- elems
the remaining elements to add.
- returns
the list buffer itself
- Definition Classes
- Growable
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use
++=
akaaddAll
instead of varargs+=
; infix operations with an operand of multiple args will be deprecated
- def -=(elem1: A, elem2: A, elems: A*): ListBuffer.this.type
Removes two or more elements from this list buffer.
Removes two or more elements from this list buffer.
- elem1
the first element to remove.
- elem2
the second element to remove.
- elems
the remaining elements to remove.
- returns
the list buffer itself
- Definition Classes
- Shrinkable
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.3) Use
--=
akasubtractAll
instead of varargs-=
; infix operations with an operand of multiple args will be deprecated
- def /:[B](z: B)(op: (B, A) => B): B
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A])./:(z)(op)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.foldLeft instead
- final def /:[B](z: B)(op: (B, A) => B): B
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use foldLeft instead of /:
- def :\[B](z: B)(op: (A, B) => B): B
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).:\(z)(op)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.foldRight instead
- final def :\[B](z: B)(op: (A, B) => B): B
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use foldRight instead of :\
- def aggregate[B](z: => B)(seqop: (B, A) => B, combop: (B, B) => B): B
Aggregates the results of applying an operator to subsequent elements.
Aggregates the results of applying an operator to subsequent elements.
Since this method degenerates to
foldLeft
for sequential (non-parallel) collections, where the combining operation is ignored, it is advisable to preferfoldLeft
for that case.For parallel collections, use the
aggregate
method specified byscala.collection.parallel.ParIterableLike
.- B
the result type, produced by
seqop
,combop
, and by this function as a final result.- z
the start value, a neutral element for
seqop
.- seqop
the binary operator used to accumulate the result.
- combop
an associative operator for combining sequential results, unused for sequential collections.
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) For sequential collections, prefer
foldLeft(z)(seqop)
. For parallel collections, useParIterableLike#aggregate
.
- final def append(elems: A*): ListBuffer.this.type
- Definition Classes
- Buffer
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use appendAll instead
- def collectFirst[B](f: PartialFunction[A, B]): Option[B]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).collectFirst(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.collectFirst(...) instead
- def companion: IterableFactory[[_]ListBuffer[_]]
- Definition Classes
- IterableOps
- Annotations
- @deprecated @deprecatedOverriding() @inline()
- Deprecated
(Since version 2.13.0) Use iterableFactory instead
- def copyToBuffer(dest: Buffer[A]): Unit
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).copyToBuffer(dest)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.copyToBuffer(...) instead
- final def copyToBuffer[B >: A](dest: Buffer[B]): Unit
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use
dest ++= coll
instead
- def count(f: (A) => Boolean): Int
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).count(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.count(...) instead
- def exists(f: (A) => Boolean): Boolean
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).exists(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.exists(...) instead
- def filter(f: (A) => Boolean): Iterator[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).filter(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.filter(...) instead
- def find(p: (A) => Boolean): Option[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).find(p)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.find instead
- def flatMap[B](f: (A) => IterableOnce[B]): IterableOnce[B]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).flatMap(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.flatMap instead or consider requiring an Iterable
- def fold[A1 >: A](z: A1)(op: (A1, A1) => A1): A1
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).fold(z)(op)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.fold instead
- def foldLeft[B](z: B)(op: (B, A) => B): B
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).foldLeft(z)(op)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.foldLeft instead
- def foldRight[B](z: B)(op: (A, B) => B): B
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).foldRight(z)(op)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.foldRight instead
- def forall(f: (A) => Boolean): Boolean
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).forall(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.forall(...) instead
- def foreach[U](f: (A) => U): Unit
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).foreach(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.foreach(...) instead
- def formatted(fmtstr: String): String
Returns string formatted according to given
format
string.Returns string formatted according to given
format
string. Format strings are as forString.format
(@see java.lang.String.format).- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toStringFormat[ListBuffer[A]] performed by method StringFormat in scala.Predef.
- Definition Classes
- StringFormat
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.12.16) Use
formatString.format(value)
instead ofvalue.formatted(formatString)
, or use thef""
string interpolator. In Java 15 and later,formatted
resolves to the new method in String which has reversed parameters.
- def hasDefiniteSize: Boolean
Tests whether this list buffer is known to have a finite size.
Tests whether this list buffer is known to have a finite size. All strict collections are known to have finite size. For a non-strict collection such as
Stream
, the predicate returnstrue
if all elements have been computed. It returnsfalse
if the stream is not yet evaluated to the end. Non-empty Iterators usually returnfalse
even if they were created from a collection with a known finite size.Note: many collection methods will not work on collections of infinite sizes. The typical failure mode is an infinite loop. These methods always attempt a traversal without checking first that
hasDefiniteSize
returnstrue
. However, checkinghasDefiniteSize
can provide an assurance that size is well-defined and non-termination is not a concern.- returns
true
if this collection is known to have finite size,false
otherwise.
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Check .knownSize instead of .hasDefiniteSize for more actionable information (see scaladoc for details)
- See also
method
knownSize
for a more useful alternative
- def isEmpty: Boolean
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).isEmpty
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.isEmpty instead
- def map[B](f: (A) => B): IterableOnce[B]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).map(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.map instead or consider requiring an Iterable
- def max(implicit ord: math.Ordering[A]): A
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).max(ord)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.max instead
- def maxBy[B](f: (A) => B)(implicit cmp: math.Ordering[B]): A
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).maxBy(f)(cmp)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.maxBy(...) instead
- def min(implicit ord: math.Ordering[A]): A
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).min(ord)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.min instead
- def minBy[B](f: (A) => B)(implicit cmp: math.Ordering[B]): A
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).minBy(f)(cmp)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.minBy(...) instead
- def mkString: String
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).mkString
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.mkString instead
- def mkString(sep: String): String
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).mkString(sep)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.mkString instead
- def mkString(start: String, sep: String, end: String): String
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).mkString(start, sep, end)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.mkString instead
- def nonEmpty: Boolean
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).nonEmpty
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.nonEmpty instead
- final def prefixLength(p: (A) => Boolean): Int
Returns the length of the longest prefix whose elements all satisfy some predicate.
Returns the length of the longest prefix whose elements all satisfy some predicate.
- p
the predicate used to test elements.
- returns
the length of the longest prefix of this list buffer such that every element of the segment satisfies the predicate
p
.
- Definition Classes
- SeqOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use segmentLength instead of prefixLength
- final def prepend(elems: A*): ListBuffer.this.type
- Definition Classes
- Buffer
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use prependAll instead
- def product(implicit num: math.Numeric[A]): A
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).product(num)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.product instead
- def reduce(f: (A, A) => A): A
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).reduce(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.reduce(...) instead
- def reduceLeft(f: (A, A) => A): A
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).reduceLeft(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.reduceLeft(...) instead
- def reduceLeftOption(f: (A, A) => A): Option[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).reduceLeftOption(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.reduceLeftOption(...) instead
- def reduceOption(f: (A, A) => A): Option[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).reduceOption(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.reduceOption(...) instead
- def reduceRight(f: (A, A) => A): A
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).reduceRight(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.reduceRight(...) instead
- def reduceRightOption(f: (A, A) => A): Option[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).reduceRightOption(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.reduceRightOption(...) instead
- final def repr: ListBuffer[A]
- Definition Classes
- IterableOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use coll instead of repr in a collection implementation, use the collection value itself from the outside
- def reverseMap[B](f: (A) => B): ListBuffer[B]
- Definition Classes
- SeqOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .reverseIterator.map(f).to(...) instead of .reverseMap(f)
- def sameElements[B >: A](that: IterableOnce[B]): Boolean
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).sameElements(that)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.sameElements instead
- def seq: ListBuffer.this.type
- Definition Classes
- Iterable
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Iterable.seq always returns the iterable itself
- def size: Int
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
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- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.size instead
- def sum(implicit num: math.Numeric[A]): A
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).sum(num)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.sum instead
- def to[C1](factory: Factory[A, C1]): C1
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).to(factory)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.to(factory) instead
- def toArray[B >: A](implicit arg0: ClassTag[B]): Array[B]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).toArray(arg0)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.toArray
- def toBuffer[B >: A]: Buffer[B]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
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- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.to(ArrayBuffer) instead
- def toIndexedSeq: collection.IndexedSeq[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).toIndexedSeq
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.toIndexedSeq instead
- final def toIterable: collection.Iterable[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).toIterable
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(Iterable) instead
- final def toIterable: ListBuffer.this.type
- returns
This collection as an
Iterable[A]
. No new collection will be built ifthis
is already anIterable[A]
.
- Definition Classes
- Iterable → IterableOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.7) toIterable is internal and will be made protected; its name is similar to
toList
ortoSeq
, but it doesn't copy non-immutable collections
- def toIterator: Iterator[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).toIterator
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator instead
- final def toIterator: Iterator[A]
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator instead of .toIterator
- def toList: immutable.List[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).toList
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.to(List) instead
- def toMap[K, V](implicit ev: <:<[A, (K, V)]): immutable.Map[K, V]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).toMap(ev)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.to(Map) instead
- def toSeq: immutable.Seq[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).toSeq
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(Seq) instead
- def toSet[B >: A]: immutable.Set[B]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).toSet
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(Set) instead
- def toStream: immutable.Stream[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).toStream
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(LazyList) instead
- final def toStream: immutable.Stream[A]
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .to(LazyList) instead of .toStream
- final def toTraversable: collection.Traversable[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).toTraversable
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(Iterable) instead
- final def toTraversable: collection.Traversable[A]
Converts this list buffer to an unspecified Iterable.
Converts this list buffer to an unspecified Iterable. Will return the same collection if this instance is already Iterable.
- returns
An Iterable containing all elements of this list buffer.
- Definition Classes
- IterableOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) toTraversable is internal and will be made protected; its name is similar to
toList
ortoSeq
, but it doesn't copy non-immutable collections
- def toVector: immutable.Vector[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).toVector
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(Vector) instead
- final def transform(f: (A) => A): ListBuffer.this.type
- Definition Classes
- SeqOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use
mapInPlace
on anIndexedSeq
instead
- def trimEnd(n: Int): Unit
Removes the last n elements of this buffer.
Removes the last n elements of this buffer.
- n
the number of elements to remove from the end of this buffer.
- Definition Classes
- Buffer
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.4) use dropRightInPlace instead
- def trimStart(n: Int): Unit
Removes the first n elements of this buffer.
Removes the first n elements of this buffer.
- n
the number of elements to remove from the beginning of this buffer.
- Definition Classes
- Buffer
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.4) use dropInPlace instead
- final def union[B >: A](that: collection.Seq[B]): ListBuffer[B]
Produces a new sequence which contains all elements of this list buffer and also all elements of a given sequence.
Produces a new sequence which contains all elements of this list buffer and also all elements of a given sequence.
xs union ys
is equivalent toxs ++ ys
.- B
the element type of the returned list buffer.
- that
the sequence to add.
- returns
a new collection which contains all elements of this list buffer followed by all elements of
that
.
- Definition Classes
- SeqOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use
concat
instead
- def view(from: Int, until: Int): View[A]
A view over a slice of the elements of this collection.
A view over a slice of the elements of this collection.
- Definition Classes
- IterableOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .view.slice(from, until) instead of .view(from, until)
- def withFilter(f: (A) => Boolean): Iterator[A]
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(listBuffer: IterableOnceExtensionMethods[A]).withFilter(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.withFilter(...) instead
- def →[B](y: B): (ListBuffer[A], B)
- Implicit
- This member is added by an implicit conversion from ListBuffer[A] toArrowAssoc[ListBuffer[A]] performed by method ArrowAssoc in scala.Predef.This conversion will take place only if A is a subclass of Option[Nothing] (A <: Option[Nothing]).
- Definition Classes
- ArrowAssoc
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use
->
instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.
This is the documentation for the Scala standard library.
Package structure
The scala package contains core types like
Int
,Float
,Array
orOption
which are accessible in all Scala compilation units without explicit qualification or imports.Notable packages include:
scala.collection
and its sub-packages contain Scala's collections frameworkscala.collection.immutable
- Immutable, sequential data-structures such asVector
,List
,Range
,HashMap
orHashSet
scala.collection.mutable
- Mutable, sequential data-structures such asArrayBuffer
,StringBuilder
,HashMap
orHashSet
scala.collection.concurrent
- Mutable, concurrent data-structures such asTrieMap
scala.concurrent
- Primitives for concurrent programming such asFutures
andPromises
scala.io
- Input and output operationsscala.math
- Basic math functions and additional numeric types likeBigInt
andBigDecimal
scala.sys
- Interaction with other processes and the operating systemscala.util.matching
- Regular expressionsOther packages exist. See the complete list on the right.
Additional parts of the standard library are shipped as separate libraries. These include:
scala.reflect
- Scala's reflection API (scala-reflect.jar)scala.xml
- XML parsing, manipulation, and serialization (scala-xml.jar)scala.collection.parallel
- Parallel collections (scala-parallel-collections.jar)scala.util.parsing
- Parser combinators (scala-parser-combinators.jar)scala.swing
- A convenient wrapper around Java's GUI framework called Swing (scala-swing.jar)Automatic imports
Identifiers in the scala package and the
scala.Predef
object are always in scope by default.Some of these identifiers are type aliases provided as shortcuts to commonly used classes. For example,
List
is an alias forscala.collection.immutable.List
.Other aliases refer to classes provided by the underlying platform. For example, on the JVM,
String
is an alias forjava.lang.String
.