object Array extends java.io.Serializable
Utility methods for operating on arrays. For example:
val a = Array(1, 2) val b = Array.ofDim[Int](2) val c = Array.concat(a, b)
where the array objects a
, b
and c
have respectively the values
Array(1, 2)
, Array(0, 0)
and Array(1, 2, 0, 0)
.
- Source
- Array.scala
- Alphabetic
- By Inheritance
- Array
- Serializable
- AnyRef
- Any
- Hide All
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- Public
- Protected
Type Members
- final class UnapplySeqWrapper[T] extends AnyVal
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
- 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
- def apply(x: Unit, xs: Unit*): Array[Unit]
Creates an array of
Unit
objects - def apply(x: Double, xs: Double*): Array[Double]
Creates an array of
Double
objects - def apply(x: Float, xs: Float*): Array[Float]
Creates an array of
Float
objects - def apply(x: Long, xs: Long*): Array[Long]
Creates an array of
Long
objects - def apply(x: Int, xs: Int*): Array[Int]
Creates an array of
Int
objects - def apply(x: Char, xs: Char*): Array[Char]
Creates an array of
Char
objects - def apply(x: Short, xs: Short*): Array[Short]
Creates an array of
Short
objects - def apply(x: Byte, xs: Byte*): Array[Byte]
Creates an array of
Byte
objects - def apply(x: Boolean, xs: Boolean*): Array[Boolean]
Creates an array of
Boolean
objects - def apply[T](xs: T*)(implicit arg0: ClassTag[T]): Array[T]
Creates an array with given elements.
Creates an array with given elements.
- xs
the elements to put in the array
- returns
an array containing all elements from xs.
- 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 clone(): AnyRef
Create a copy of the receiver object.
Create a copy of the receiver object.
The default implementation of the
clone
method is platform dependent.- returns
a copy of the receiver object.
- def concat[T](xss: Array[T]*)(implicit arg0: ClassTag[T]): Array[T]
Concatenates all arrays into a single array.
Concatenates all arrays into a single array.
- xss
the given arrays
- returns
the array created from concatenating
xss
- def copy(src: AnyRef, srcPos: Int, dest: AnyRef, destPos: Int, length: Int): Unit
Copy one array to another.
Copy one array to another. Equivalent to Java's
System.arraycopy(src, srcPos, dest, destPos, length)
, except that this also works for polymorphic and boxed arrays.Note that the passed-in
dest
array will be modified by this call.- src
the source array.
- srcPos
starting position in the source array.
- dest
destination array.
- destPos
starting position in the destination array.
- length
the number of array elements to be copied.
- See also
java.lang.System#arraycopy
- def copyAs[A](original: Array[_], newLength: Int)(implicit ct: ClassTag[A]): Array[A]
Copy one array to another, truncating or padding with default values (if necessary) so the copy has the specified length.
Copy one array to another, truncating or padding with default values (if necessary) so the copy has the specified length. The new array can have a different type than the original one as long as the values are assignment-compatible. When copying between primitive and object arrays, boxing and unboxing are supported.
Equivalent to Java's
java.util.Arrays.copyOf(original, newLength, newType)
, except that this works for all combinations of primitive and object arrays in a single method.- See also
java.util.Arrays#copyOf
- def copyOf[A](original: Array[A], newLength: Int): Array[A]
Copy one array to another, truncating or padding with default values (if necessary) so the copy has the specified length.
Copy one array to another, truncating or padding with default values (if necessary) so the copy has the specified length.
Equivalent to Java's
java.util.Arrays.copyOf(original, newLength)
, except that this works for primitive and object arrays in a single method.- See also
java.util.Arrays#copyOf
- def empty[T](implicit arg0: ClassTag[T]): Array[T]
Returns an array of length 0
- val emptyBooleanArray: Array[Boolean]
- val emptyByteArray: Array[Byte]
- val emptyCharArray: Array[Char]
- val emptyDoubleArray: Array[Double]
- val emptyFloatArray: Array[Float]
- val emptyIntArray: Array[Int]
- val emptyLongArray: Array[Long]
- val emptyObjectArray: Array[AnyRef]
- val emptyShortArray: Array[Short]
- 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(xs: Array[AnyRef], ys: Array[AnyRef]): Boolean
- def equals(arg0: AnyRef): Boolean
The equality method for reference types.
- def fill[T](n1: Int, n2: Int, n3: Int, n4: Int, n5: Int)(elem: => T)(implicit arg0: ClassTag[T]): Array[Array[Array[Array[Array[T]]]]]
Returns a five-dimensional array that contains the results of some element computation a number of times.
Returns a five-dimensional array that contains the results of some element computation a number of times.
- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- n3
the number of elements in the 3rd dimension
- n4
the number of elements in the 4th dimension
- n5
the number of elements in the 5th dimension
- elem
the element computation
- def fill[T](n1: Int, n2: Int, n3: Int, n4: Int)(elem: => T)(implicit arg0: ClassTag[T]): Array[Array[Array[Array[T]]]]
Returns a four-dimensional array that contains the results of some element computation a number of times.
Returns a four-dimensional array that contains the results of some element computation a number of times.
- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- n3
the number of elements in the 3rd dimension
- n4
the number of elements in the 4th dimension
- elem
the element computation
- def fill[T](n1: Int, n2: Int, n3: Int)(elem: => T)(implicit arg0: ClassTag[T]): Array[Array[Array[T]]]
Returns a three-dimensional array that contains the results of some element computation a number of times.
Returns a three-dimensional array that contains the results of some element computation a number of times.
- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- n3
the number of elements in the 3rd dimension
- elem
the element computation
- def fill[T](n1: Int, n2: Int)(elem: => T)(implicit arg0: ClassTag[T]): Array[Array[T]]
Returns a two-dimensional array that contains the results of some element computation a number of times.
Returns a two-dimensional array that contains the results of some element computation a number of times.
- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- elem
the element computation
- def fill[T](n: Int)(elem: => T)(implicit arg0: ClassTag[T]): Array[T]
Returns an array that contains the results of some element computation a number of times.
Returns an array that contains the results of some element computation a number of times.
Note that this means that
elem
is computed a total of n times:scala> Array.fill(3){ math.random } res3: Array[Double] = Array(0.365461167592537, 1.550395944913685E-4, 0.7907242137333306)
- n
the number of elements desired
- elem
the element computation
- returns
an Array of size n, where each element contains the result of computing
elem
.
- 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 from[A](it: IterableOnce[A])(implicit arg0: ClassTag[A]): Array[A]
- 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 is
T0
.Test whether the dynamic type of the receiver object is
T0
.Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression
1.isInstanceOf[String]
will returnfalse
, while the expressionList(1).isInstanceOf[List[String]]
will returntrue
. 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 specified type.- returns
true
if the receiver object is an instance of erasure of typeT0
;false
otherwise.
- Definition Classes
- Any
- def iterate[T](start: T, len: Int)(f: (T) => T)(implicit arg0: ClassTag[T]): Array[T]
Returns an array containing repeated applications of a function to a start value.
Returns an array containing repeated applications of a function to a start value.
- start
the start value of the array
- len
the number of elements returned by the array
- f
the function that is repeatedly applied
- returns
the array returning
len
values in the sequencestart, f(start), f(f(start)), ...
- 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 newBuilder[T](implicit t: ClassTag[T]): ArrayBuilder[T]
Returns a new scala.collection.mutable.ArrayBuilder.
- 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 ofDim[T](n1: Int, n2: Int, n3: Int, n4: Int, n5: Int)(implicit arg0: ClassTag[T]): Array[Array[Array[Array[Array[T]]]]]
Creates a 5-dimensional array
- def ofDim[T](n1: Int, n2: Int, n3: Int, n4: Int)(implicit arg0: ClassTag[T]): Array[Array[Array[Array[T]]]]
Creates a 4-dimensional array
- def ofDim[T](n1: Int, n2: Int, n3: Int)(implicit arg0: ClassTag[T]): Array[Array[Array[T]]]
Creates a 3-dimensional array
- def ofDim[T](n1: Int, n2: Int)(implicit arg0: ClassTag[T]): Array[Array[T]]
Creates a 2-dimensional array
- def ofDim[T](n1: Int)(implicit arg0: ClassTag[T]): Array[T]
Creates array with given dimensions
- def range(start: Int, end: Int, step: Int): Array[Int]
Returns an array containing equally spaced values in some integer interval.
Returns an array containing equally spaced values in some integer interval.
- start
the start value of the array
- end
the end value of the array, exclusive (in other words, this is the first value not returned)
- step
the increment value of the array (may not be zero)
- returns
the array with values in
start, start + step, ...
up to, but excludingend
- def range(start: Int, end: Int): Array[Int]
Returns an array containing a sequence of increasing integers in a range.
Returns an array containing a sequence of increasing integers in a range.
- start
the start value of the array
- end
the end value of the array, exclusive (in other words, this is the first value not returned)
- returns
the array with values in range
start, start + 1, ..., end - 1
up to, but excluding,end
.
- final def synchronized[T0](arg0: => T0): T0
- Definition Classes
- AnyRef
- def tabulate[T](n1: Int, n2: Int, n3: Int, n4: Int, n5: Int)(f: (Int, Int, Int, Int, Int) => T)(implicit arg0: ClassTag[T]): Array[Array[Array[Array[Array[T]]]]]
Returns a five-dimensional array containing values of a given function over ranges of integer values starting from
0
.Returns a five-dimensional array containing values of a given function over ranges of integer values starting from
0
.- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- n3
the number of elements in the 3rd dimension
- n4
the number of elements in the 4th dimension
- n5
the number of elements in the 5th dimension
- f
The function computing element values
- def tabulate[T](n1: Int, n2: Int, n3: Int, n4: Int)(f: (Int, Int, Int, Int) => T)(implicit arg0: ClassTag[T]): Array[Array[Array[Array[T]]]]
Returns a four-dimensional array containing values of a given function over ranges of integer values starting from
0
.Returns a four-dimensional array containing values of a given function over ranges of integer values starting from
0
.- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- n3
the number of elements in the 3rd dimension
- n4
the number of elements in the 4th dimension
- f
The function computing element values
- def tabulate[T](n1: Int, n2: Int, n3: Int)(f: (Int, Int, Int) => T)(implicit arg0: ClassTag[T]): Array[Array[Array[T]]]
Returns a three-dimensional array containing values of a given function over ranges of integer values starting from
0
.Returns a three-dimensional array containing values of a given function over ranges of integer values starting from
0
.- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- n3
the number of elements in the 3rd dimension
- f
The function computing element values
- def tabulate[T](n1: Int, n2: Int)(f: (Int, Int) => T)(implicit arg0: ClassTag[T]): Array[Array[T]]
Returns a two-dimensional array containing values of a given function over ranges of integer values starting from
0
.Returns a two-dimensional array containing values of a given function over ranges of integer values starting from
0
.- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- f
The function computing element values
- def tabulate[T](n: Int)(f: (Int) => T)(implicit arg0: ClassTag[T]): Array[T]
Returns an array containing values of a given function over a range of integer values starting from 0.
Returns an array containing values of a given function over a range of integer values starting from 0.
- n
The number of elements in the array
- f
The function computing element values
- returns
A traversable consisting of elements
f(0),f(1), ..., f(n - 1)
- implicit def toFactory[A](dummy: Array.type)(implicit arg0: ClassTag[A]): Factory[A, Array[A]]
Provides an implicit conversion from the Array object to a collection Factory
- 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
- def unapplySeq[T](x: Array[T]): UnapplySeqWrapper[T]
Called in a pattern match like
{ case Array(x,y,z) => println('3 elements')}
.Called in a pattern match like
{ case Array(x,y,z) => println('3 elements')}
.- x
the selector value
- returns
sequence wrapped in a scala.Some, if
x
is an Array, otherwiseNone
- final def wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- final def wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- final def wait(arg0: Long): Unit
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
.