abstract final class Boolean extends AnyVal
Boolean
(equivalent to Java's boolean
primitive type) is a
subtype of scala.AnyVal. Instances of Boolean
are not
represented by an object in the underlying runtime system.
There is an implicit conversion from scala.Boolean => scala.runtime.RichBoolean which provides useful non-primitive operations.
- Source
- Boolean.scala
- Alphabetic
- By Inheritance
- Boolean
- AnyVal
- Any
- by boolean2Boolean
- by booleanWrapper
- by any2stringadd
- by StringFormat
- by Ensuring
- by ArrowAssoc
- Hide All
- Show All
- Public
- Protected
Abstract Value Members
- abstract def !=(x: Boolean): Boolean
Compares two Boolean expressions and returns
true
if they evaluate to a different value.Compares two Boolean expressions and returns
true
if they evaluate to a different value.a != b
returnstrue
if and only ifa
istrue
andb
isfalse
ora
isfalse
andb
istrue
.
- abstract def &(x: Boolean): Boolean
Compares two Boolean expressions and returns
true
if both of them evaluate to true.Compares two Boolean expressions and returns
true
if both of them evaluate to true.a & b
returnstrue
if and only ifa
andb
aretrue
.
- Note
This method evaluates both
a
andb
, even if the result is already determined after evaluatinga
.
- abstract def &&(x: Boolean): Boolean
Compares two Boolean expressions and returns
true
if both of them evaluate to true.Compares two Boolean expressions and returns
true
if both of them evaluate to true.a && b
returnstrue
if and only ifa
andb
aretrue
.
- Note
This method uses 'short-circuit' evaluation and behaves as if it was declared as
def &&(x: => Boolean): Boolean
. Ifa
evaluates tofalse
,false
is returned without evaluatingb
.
- abstract def ==(x: Boolean): Boolean
Compares two Boolean expressions and returns
true
if they evaluate to the same value.Compares two Boolean expressions and returns
true
if they evaluate to the same value.a == b
returnstrue
if and only ifa
andb
aretrue
ora
andb
arefalse
.
- abstract def ^(x: Boolean): Boolean
Compares two Boolean expressions and returns
true
if they evaluate to a different value.Compares two Boolean expressions and returns
true
if they evaluate to a different value.a ^ b
returns
trueif and only if
a
istrue
andb
isfalse
ora
isfalse
andb
istrue
.
- abstract def unary_!: Boolean
Negates a Boolean expression.
Negates a Boolean expression.
-
!a
results infalse
if and only ifa
evaluates totrue
and -!a
results intrue
if and only ifa
evaluates tofalse
.- returns
the negated expression
- abstract def |(x: Boolean): Boolean
Compares two Boolean expressions and returns
true
if one or both of them evaluate to true.Compares two Boolean expressions and returns
true
if one or both of them evaluate to true.a | b
returnstrue
if and only ifa
istrue
orb
istrue
ora
andb
aretrue
.
- Note
This method evaluates both
a
andb
, even if the result is already determined after evaluatinga
.
- abstract def ||(x: Boolean): Boolean
Compares two Boolean expressions and returns
true
if one or both of them evaluate to true.Compares two Boolean expressions and returns
true
if one or both of them evaluate to true.a || b
returnstrue
if and only ifa
istrue
orb
istrue
ora
andb
aretrue
.
- Note
This method uses 'short-circuit' evaluation and behaves as if it was declared as
def ||(x: => Boolean): Boolean
. Ifa
evaluates totrue
,true
is returned without evaluatingb
.
Concrete Value Members
- def <(that: Boolean): Boolean
Returns true if
this
is less thanthat
- def <=(that: Boolean): Boolean
Returns true if
this
is less than or equal tothat
. - def >(that: Boolean): Boolean
Returns true if
this
is greater thanthat
. - def >=(that: Boolean): Boolean
Returns true if
this
is greater than or equal tothat
. - def booleanValue(): Boolean
- Implicit
- This member is added by an implicit conversion from Boolean tojava.lang.Boolean performed by method boolean2Boolean in scala.Predef.
- Definition Classes
- Boolean
- def compare(y: Boolean): Int
Result of comparing
this
with operandthat
.Result of comparing
this
with operandthat
.Implement this method to determine how instances of A will be sorted.
Returns
x
where:x < 0
whenthis < that
x == 0
whenthis == that
x > 0
whenthis > that
- def compareTo(arg0: java.lang.Boolean): Int
- Implicit
- This member is added by an implicit conversion from Boolean tojava.lang.Boolean performed by method boolean2Boolean in scala.Predef.
- Definition Classes
- Boolean → Comparable
- def compareTo(that: Boolean): Int
Result of comparing
this
with operandthat
. - def getClass(): Class[Boolean]
Returns the runtime class representation of the object.
- val self: Boolean
Shadowed Implicit Value Members
- def equals(arg0: AnyRef): Boolean
The equality method for reference types.
The equality method for reference types. Default implementation delegates to
eq
.See also
equals
in scala.Any.- returns
true
if the receiver object is equivalent to the argument;false
otherwise.
- Implicit
- This member is added by an implicit conversion from Boolean tojava.lang.Boolean performed by method boolean2Boolean in scala.Predef.
- 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:(boolean: java.lang.Boolean).equals(arg0)
- Definition Classes
- Boolean → AnyRef → Any
- def hashCode(): Int
The hashCode method for reference types.
The hashCode method for reference types. See hashCode in scala.Any.
- returns
the hash code value for this object.
- Implicit
- This member is added by an implicit conversion from Boolean tojava.lang.Boolean performed by method boolean2Boolean in scala.Predef.
- 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:(boolean: java.lang.Boolean).hashCode()
- Definition Classes
- Boolean → AnyRef → Any
- 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.
- Implicit
- This member is added by an implicit conversion from Boolean tojava.lang.Boolean performed by method boolean2Boolean in scala.Predef.
- 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:(boolean: java.lang.Boolean).toString()
- Definition Classes
- Boolean → AnyRef → Any
- def toString(): String
Returns a string representation of the object.
Returns a string representation of the object.
The default representation is platform dependent.
- returns
a string representation of the object.
- Implicit
- This member is added by an implicit conversion from Boolean toRichBoolean performed by method booleanWrapper in scala.LowPriorityImplicits.
- 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:(boolean: RichBoolean).toString()
- Definition Classes
- Proxy → Any
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
.