object StdIn extends StdIn
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- StdIn.scala
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- final def !=(arg0: Any): Boolean
Test two objects for inequality.
Test two objects for inequality.
- returns
trueif !(this == that), false otherwise.
- Definition Classes
- AnyRef → Any
- final def ##: Int
Equivalent to
x.hashCodeexcept for boxed numeric types andnull.Equivalent to
x.hashCodeexcept 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. Fornullreturns a hashcode wherenull.hashCodethrows aNullPointerException.- returns
a hash value consistent with ==
- Definition Classes
- AnyRef → Any
- final def ==(arg0: Any): Boolean
The expression
x == thatis equivalent toif (x eq null) that eq null else x.equals(that).The expression
x == thatis equivalent toif (x eq null) that eq null else x.equals(that).- returns
trueif the receiver object is equivalent to the argument;falseotherwise.
- Definition Classes
- AnyRef → Any
- 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 aClassCastExceptionat 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
ClassCastExceptionif the receiver object is not an instance of the erasure of typeT0.
- def clone(): AnyRef
Create a copy of the receiver object.
Create a copy of the receiver object.
The default implementation of the
clonemethod is platform dependent.- returns
a copy of the receiver object.
- 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
eqmethod implements an equivalence relation on non-null instances ofAnyRef, and has three additional properties:- It is consistent: for any non-null instances
xandyof typeAnyRef, multiple invocations ofx.eq(y)consistently returnstrueor consistently returnsfalse. - For any non-null instance
xof typeAnyRef,x.eq(null)andnull.eq(x)returnsfalse. null.eq(null)returnstrue.
When overriding the
equalsorhashCodemethods, 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
trueif the argument is a reference to the receiver object;falseotherwise.
- Definition Classes
- AnyRef
- It is consistent: for any non-null instances
- def equals(arg0: AnyRef): Boolean
The equality method for reference types.
- 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
finalizemethod is invoked, as well as the interaction betweenfinalizeand 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
- final def getClass(): Class[_ <: AnyRef]
Returns the runtime class representation of the object.
- def hashCode(): Int
The hashCode method for reference types.
- 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
T0is, the test is done in one of the below ways:T0is a non-parameterized class type, e.g.BigDecimal: this method returnstrueif the value of the receiver object is aBigDecimalor a subtype ofBigDecimal.T0is a parameterized class type, e.g.List[Int]: this method returnstrueif the value of the receiver object is someList[X]for anyX. For example,List(1, 2, 3).isInstanceOf[List[String]]will return true.T0is some singleton typex.typeor literalx: this method returnsthis.eq(x). For example,x.isInstanceOf[1]is equivalent tox.eq(1)T0is an intersectionX with YorX & Y: this method is equivalent tox.isInstanceOf[X] && x.isInstanceOf[Y]T0is a unionX | Y: this method is equivalent tox.isInstanceOf[X] || x.isInstanceOf[Y]T0is a type parameter or an abstract type member: this method is equivalent toisInstanceOf[U]whereUisT0's upper bound,AnyifT0is unbounded. For example,x.isInstanceOf[A]whereAis an unbounded type parameter will return true for any value ofx.
This is exactly equivalent to the type pattern
_: T0- returns
trueif the receiver object is an instance of erasure of typeT0;falseotherwise.
- Definition Classes
- Any
- Note
due to the unexpectedness of
List(1, 2, 3).isInstanceOf[List[String]]returning true andx.isInstanceOf[A]whereAis a type parameter or abstract member returning true, these forms issue a warning.
- final def ne(arg0: AnyRef): Boolean
Equivalent to
!(this eq that).Equivalent to
!(this eq that).- returns
trueif the argument is not a reference to the receiver object;falseotherwise.
- Definition Classes
- AnyRef
- 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 readBoolean(): Boolean
Reads a boolean value from an entire line of the default input.
Reads a boolean value from an entire line of the default input. Has a fairly liberal interpretation of the input.
- returns
the boolean value read, or false if it couldn't be converted to a boolean
- Definition Classes
- StdIn
- Exceptions thrown
java.io.EOFExceptionif the end of the input stream has been reached.
- def readByte(): Byte
Reads a byte value from an entire line of the default input.
Reads a byte value from an entire line of the default input.
- returns
the Byte that was read
- Definition Classes
- StdIn
- Exceptions thrown
java.io.EOFExceptionif the end of the input stream has been reached.java.lang.NumberFormatExceptionif the value couldn't be converted to a Byte
- def readChar(): Char
Reads a char value from an entire line of the default input.
Reads a char value from an entire line of the default input.
- returns
the Char that was read
- Definition Classes
- StdIn
- Exceptions thrown
java.io.EOFExceptionif the end of the input stream has been reached.java.lang.StringIndexOutOfBoundsExceptionif the line read from default input was empty
- def readDouble(): Double
Reads a double value from an entire line of the default input.
Reads a double value from an entire line of the default input.
- returns
the Double that was read.
- Definition Classes
- StdIn
- Exceptions thrown
java.io.EOFExceptionif the end of the input stream has been reached.java.lang.NumberFormatExceptionif the value couldn't be converted to a Float
- def readFloat(): Float
Reads a float value from an entire line of the default input.
Reads a float value from an entire line of the default input.
- returns
the Float that was read.
- Definition Classes
- StdIn
- Exceptions thrown
java.io.EOFExceptionif the end of the input stream has been reached.java.lang.NumberFormatExceptionif the value couldn't be converted to a Float
- def readInt(): Int
Reads an int value from an entire line of the default input.
Reads an int value from an entire line of the default input.
- returns
the Int that was read
- Definition Classes
- StdIn
- Exceptions thrown
java.io.EOFExceptionif the end of the input stream has been reached.java.lang.NumberFormatExceptionif the value couldn't be converted to an Int
- def readLine(text: String, args: Any*): String
Print and flush formatted text to the default output, and read a full line from the default input.
Print and flush formatted text to the default output, and read a full line from the default input. Returns
nullif the end of the input stream has been reached.- text
the format of the text to print out, as in
printf.- args
the parameters used to instantiate the format, as in
printf.- returns
the string read from the default input
- Definition Classes
- StdIn
- def readLine(): String
Read a full line from the default input.
Read a full line from the default input. Returns
nullif the end of the input stream has been reached.- returns
the string read from the terminal or null if the end of stream was reached.
- Definition Classes
- StdIn
- def readLong(): Long
Reads an long value from an entire line of the default input.
Reads an long value from an entire line of the default input.
- returns
the Long that was read
- Definition Classes
- StdIn
- Exceptions thrown
java.io.EOFExceptionif the end of the input stream has been reached.java.lang.NumberFormatExceptionif the value couldn't be converted to a Long
- def readShort(): Short
Reads a short value from an entire line of the default input.
Reads a short value from an entire line of the default input.
- returns
the short that was read
- Definition Classes
- StdIn
- Exceptions thrown
java.io.EOFExceptionif the end of the input stream has been reached.java.lang.NumberFormatExceptionif the value couldn't be converted to a Short
- def readf(format: String): List[Any]
Reads in some structured input (from the default input), specified by a format specifier.
Reads in some structured input (from the default input), specified by a format specifier. See class
java.text.MessageFormatfor details of the format specification.- format
the format of the input.
- returns
a list of all extracted values.
- Definition Classes
- StdIn
- Exceptions thrown
java.io.EOFExceptionif the end of the input stream has been reached.
- def readf1(format: String): Any
Reads in some structured input (from the default input), specified by a format specifier, returning only the first value extracted, according to the format specification.
Reads in some structured input (from the default input), specified by a format specifier, returning only the first value extracted, according to the format specification.
- format
format string, as accepted by
readf.- returns
The first value that was extracted from the input
- Definition Classes
- StdIn
- def readf2(format: String): (Any, Any)
Reads in some structured input (from the default input), specified by a format specifier, returning only the first two values extracted, according to the format specification.
Reads in some structured input (from the default input), specified by a format specifier, returning only the first two values extracted, according to the format specification.
- format
format string, as accepted by
readf.- returns
A scala.Tuple2 containing the first two values extracted
- Definition Classes
- StdIn
- def readf3(format: String): (Any, Any, Any)
Reads in some structured input (from the default input), specified by a format specifier, returning only the first three values extracted, according to the format specification.
Reads in some structured input (from the default input), specified by a format specifier, returning only the first three values extracted, according to the format specification.
- format
format string, as accepted by
readf.- returns
A scala.Tuple3 containing the first three values extracted
- Definition Classes
- StdIn
- final def synchronized[T0](arg0: => T0): T0
Executes the code in
bodywith an exclusive lock onthis.Executes the code in
bodywith an exclusive lock onthis.- returns
the result of
body
- Definition Classes
- AnyRef
- 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.
- Definition Classes
- AnyRef → Any
- 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-.
This is the documentation for the Scala standard library.
Package structure
The scala package contains core types like
Int,Float,ArrayorOptionwhich are accessible in all Scala compilation units without explicit qualification or imports.Notable packages include:
scala.collectionand its sub-packages contain Scala's collections frameworkscala.collection.immutable- Immutable, sequential data-structures such asVector,List,Range,HashMaporHashSetscala.collection.mutable- Mutable, sequential data-structures such asArrayBuffer,StringBuilder,HashMaporHashSetscala.collection.concurrent- Mutable, concurrent data-structures such asTrieMapscala.concurrent- Primitives for concurrent programming such asFuturesandPromisesscala.io- Input and output operationsscala.math- Basic math functions and additional numeric types likeBigIntandBigDecimalscala.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.Predefobject are always in scope by default.Some of these identifiers are type aliases provided as shortcuts to commonly used classes. For example,
Listis an alias forscala.collection.immutable.List.Other aliases refer to classes provided by the underlying platform. For example, on the JVM,
Stringis an alias forjava.lang.String.