scala.Array

final class Array[T] extends java.io.Serializable with java.lang.Cloneable

Arrays are mutable, indexed collections of values. Array[T] is Scala’s representation for Java’s T[] .

val numbers = Array(1, 2, 3, 4)
val first = numbers(0) // read the first element
numbers(3) = 100 // replace the 4th array element with 100
val biggerNumbers = numbers.map(_ * 2) // multiply all numbers by two

Arrays make use of two common pieces of Scala syntactic sugar, shown on lines 2 and 3 of the above example code. Line 2 is translated into a call to apply(Int) , while line 3 is translated into a call to update(Int, T) .

Two implicit conversions exist in scala.Predef that are frequently applied to arrays: a conversion to scala.collection.mutable.ArrayOps (shown on line 4 of the example above) and a conversion to scala.collection.mutable.WrappedArray (a subtype of scala.collection.Seq). Both types make available many of the standard operations found in the Scala collections API. The conversion to ArrayOps is temporary, as all operations defined on ArrayOps return an Array , while the conversion to WrappedArray is permanent as all operations return a WrappedArray .

The conversion to ArrayOps takes priority over the conversion to WrappedArray . For instance, consider the following code:

val arr = Array(1, 2, 3)
val arrReversed = arr.reverse
val seqReversed : Seq[Int] = arr.reverse

Value arrReversed will be of type Array[Int] , with an implicit conversion to ArrayOps occurring to perform the reverse operation. The value of seqReversed , on the other hand, will be computed by converting to WrappedArray first and invoking the variant of reverse that returns another WrappedArray .

• Source
  • Array.scala - Blame
  • Array.scala - History
• Version
  • 1.0
• See also
  • “The Scala 2.8 Collections’ API” section on Array by Martin Odersky for more information. “Scala 2.8 Arrays” the Scala Improvement Document detailing arrays since Scala 2.8. Scala Language Specification, for in-depth information on the transformations the Scala compiler makes on Arrays (Sections 6.6 and 6.15 respectively.)

Instance Constructors From scala.Array

new Array(_length: Int)

(defined at scala.Array)

Value Members From scala.Array

def apply(i: Int): T

The element at given index.

Indices start at 0 ; xs.apply(0) is the first element of array xs . Note the indexing syntax xs(i) is a shorthand for xs.apply(i) .

• i
  • the index
• returns
  • the element at the given index
• Exceptions thrown
  • ArrayIndexOutOfBoundsException if i < 0 or length <= i

(defined at scala.Array)

def update(i: Int, x: T): Unit

Update the element at given index.

Indices start at 0 ; xs.update(i, x) replaces the i ^th element in the array. Note the syntax xs(i) = x is a shorthand for xs.update(i, x) .

• i
  • the index
• x
  • the value to be written at index i
• Exceptions thrown
  • ArrayIndexOutOfBoundsException if i < 0 or length <= i

(defined at scala.Array)

Value Members From Implicit scala.Predef.ArrayCharSequence

def charAt(index: Int): Char

• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayCharSequence performed by method ArrayCharSequence in scala.Predef. This conversion will take place only if T is Char (T =:= Char).
• Definition Classes
  • ArrayCharSequence → CharSequence

(added by implicit convertion: scala.Predef.ArrayCharSequence)

def chars(): IntStream

• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayCharSequence performed by method ArrayCharSequence in scala.Predef. This conversion will take place only if T is Char (T =:= Char).
• Definition Classes
  • CharSequence

(added by implicit convertion: scala.Predef.ArrayCharSequence)

def codePoints(): IntStream

• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayCharSequence performed by method ArrayCharSequence in scala.Predef. This conversion will take place only if T is Char (T =:= Char).
• Definition Classes
  • CharSequence

(added by implicit convertion: scala.Predef.ArrayCharSequence)

def subSequence(start: Int, end: Int): CharSequence

• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayCharSequence performed by method ArrayCharSequence in scala.Predef. This conversion will take place only if T is Char (T =:= Char).
• Definition Classes
  • ArrayCharSequence → CharSequence

(added by implicit convertion: scala.Predef.ArrayCharSequence)

Value Members From Implicit scala.Predef.genericArrayOps

def ++:[B >: A, That](that: collection.Traversable[B])(implicit bf: CanBuildFrom[Array[T], B, That]): That

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.

Example:

scala> val x = List(1)
x: List[Int] = List(1)

scala> val y = LinkedList(2)
y: scala.collection.mutable.LinkedList[Int] = LinkedList(2)

scala> val z = x ++: y
z: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2)

This overload exists because: for the implementation of ++: we should reuse that of ++ because many collections override it with more efficient versions.

Since TraversableOnce has no ++ method, we have to implement that directly, but Traversable and down can use the overload.

• B
  • the element type of the returned collection.
• That
  • the class of the returned collection. Where possible, That is the same class as the current collection class Repr , but this depends on the element type B being admissible for that class, which means that an implicit instance of type CanBuildFrom[Repr, B, That] is found.
• that
  • the traversable to append.
• bf
  • an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type B .
• returns
  • a new collection of type That which contains all elements of this mutable indexed sequence followed by all elements of that .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def ++:[B >: A, That](that: collection.TraversableOnce[B])(implicit bf: CanBuildFrom[Array[T], B, That]): That

[use case]

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.

Example:

scala> val x = List(1)
x: List[Int] = List(1)

scala> val y = LinkedList(2)
y: scala.collection.mutable.LinkedList[Int] = LinkedList(2)

scala> val z = x ++: y
z: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2)

• B
  • the element type of the returned collection.
• that
  • the traversable to append.
• returns
  • a new array which contains all elements of this array followed by all elements of that .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def ++[B >: A, That](that: GenTraversableOnce[B])(implicit bf: CanBuildFrom[Array[T], B, That]): That

[use case]

Returns a new array containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the array is the most specific superclass encompassing the element types of the two operands.

Example:

scala> val a = List(1)
a: List[Int] = List(1)

scala> val b = List(2)
b: List[Int] = List(2)

scala> val c = a ++ b
c: List[Int] = List(1, 2)

scala> val d = List('a')
d: List[Char] = List(a)

scala> val e = c ++ d
e: List[AnyVal] = List(1, 2, a)

• B
  • the element type of the returned collection.
• that
  • the traversable to append.
• returns
  • a new array which contains all elements of this array followed by all elements of that .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def +:[B >: A, That](elem: B)(implicit bf: CanBuildFrom[Array[T], B, That]): That

[use case]

A copy of the array with an element prepended.

Note that :-ending operators are right associative (see example). A mnemonic for +: vs. :+ is: the COLon goes on the COLlection side.

Also, the original array 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)

• elem
  • the prepended element
• returns
  • a new array consisting of elem followed by all elements of this array.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def +:[B >: T](elem: B)(implicit arg0: ClassTag[B]): Array[B]

• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • ArrayOps

(added by implicit convertion: scala.Predef.genericArrayOps)

def /:[B](z: B)(op: (B, T) ⇒ B): B

Applies a binary operator to a start value and all elements of this mutable indexed sequence, going left to right.

Note: /: is alternate syntax for foldLeft ; z /: xs is the same as xs foldLeft z .

Examples:

Note that the folding function used to compute b is equivalent to that used to compute c.

scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)

scala> val b = (5 /: a)(_+_)
b: Int = 15

scala> val c = (5 /: a)((x,y) => x + y)
c: Int = 15

• B
  • the result type of the binary operator.
• z
  • the start value.
• op
  • the binary operator.
• returns
  • the result of inserting op between consecutive elements of this mutable indexed sequence, going left to right with the start value z on the left:

    op(...op(op(z, x_1), x_2), ..., x_n)
    

where `x1, ..., xn` are the elements of this mutable indexed sequence.

• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def :+[B >: A, That](elem: B)(implicit bf: CanBuildFrom[Array[T], B, That]): That

[use case]

A copy of this array with an element appended.

A mnemonic for +: vs. :+ is: the COLon goes on the COLlection side.

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)

• elem
  • the appended element
• returns
  • a new array consisting of all elements of this array followed by elem .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def :+[B >: T](elem: B)(implicit arg0: ClassTag[B]): Array[B]

• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • ArrayOps

(added by implicit convertion: scala.Predef.genericArrayOps)

def :\[B](z: B)(op: (T, B) ⇒ B): B

Applies a binary operator to all elements of this mutable indexed sequence and a start value, going right to left.

Note: :\ is alternate syntax for foldRight ; xs :\ z is the same as xs foldRight z .

Examples:

Note that the folding function used to compute b is equivalent to that used to compute c.

scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)

scala> val b = (a :\ 5)(_+_)
b: Int = 15

scala> val c = (a :\ 5)((x,y) => x + y)
c: Int = 15

• B
  • the result type of the binary operator.
• z
  • the start value
• op
  • the binary operator
• returns
  • the result of inserting op between consecutive elements of this mutable indexed sequence, going right to left with the start value z on the right:

    op(x_1, op(x_2, ... op(x_n, z)...))
    

where `x1, ..., xn` are the elements of this mutable indexed sequence.

• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def addString(b: StringBuilder): StringBuilder

Appends all elements of this mutable indexed sequence to a string builder. The written text consists of the string representations (w.r.t. the method toString ) of all elements of this mutable indexed sequence 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.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def addString(b: StringBuilder, sep: String): StringBuilder

Appends all elements of this mutable indexed sequence 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 mutable indexed sequence, separated by the string sep .

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.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def addString(b: StringBuilder, start: String, sep: String, end: String): StringBuilder

Appends all elements of this mutable indexed sequence to a string builder using start, end, and separator strings. The written text begins with the string start and ends with the string end . Inside, the string representations (w.r.t. the method toString ) of all elements of this mutable indexed sequence are separated by the string sep .

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.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def aggregate[B](z: ⇒ B)(seqop: (B, T) ⇒ B, combop: (B, B) ⇒ B): B

Aggregates the results of applying an operator to subsequent elements.

This is a more general form of fold and reduce . It is similar to foldLeft in that it doesn’t require the result to be a supertype of the element type. In addition, it allows parallel collections to be processed in chunks, and then combines the intermediate results.

aggregate splits the mutable indexed sequence into partitions and processes each partition by sequentially applying seqop , starting with z (like foldLeft ). Those intermediate results are then combined by using combop (like fold ). The implementation of this operation may operate on an arbitrary number of collection partitions (even 1), so combop may be invoked an arbitrary number of times (even 0).

As an example, consider summing up the integer values of a list of chars. The initial value for the sum is 0. First, seqop transforms each input character to an Int and adds it to the sum (of the partition). Then, combop just needs to sum up the intermediate results of the partitions:

List('a', 'b', 'c').aggregate(0)({ (sum, ch) => sum + ch.toInt }, { (p1, p2) => p1 + p2 })

• B
  • the type of accumulated results
• z
  • the initial value for the accumulated result of the partition - this will typically be the neutral element for the seqop operator (e.g. Nil for list concatenation or 0 for summation) and may be evaluated more than once
• seqop
  • an operator used to accumulate results within a partition
• combop
  • an associative operator used to combine results from different partitions
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def canEqual(that: Any): Boolean

Method called from equality methods, so that user-defined subclasses can refuse to be equal to other collections of the same kind.

• that
  • The object with which this mutable indexed sequence should be compared
• returns
  • true , if this mutable indexed sequence can possibly equal that , false otherwise. The test takes into consideration only the run-time types of objects but ignores their elements.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IterableLike → Equals

(added by implicit convertion: scala.Predef.genericArrayOps)

def collectFirst[B](pf: PartialFunction[T, B]): Option[B]

Finds the first element of the mutable indexed sequence 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.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce

Example:

Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10)

(added by implicit convertion: scala.Predef.genericArrayOps)

def collect[B, That](pf: PartialFunction[T, B])(implicit bf: CanBuildFrom[Array[T], B, That]): That

[use case]

Builds a new collection by applying a partial function to all elements of this array on which the function is defined.

• B
  • the element type of the returned collection.
• pf
  • the partial function which filters and maps the array.
• returns
  • a new array 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.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def combinations(n: Int): collection.Iterator[Array[T]]

Iterates over combinations. A combination of length n is a subsequence of the original sequence, with the elements taken in order. Thus, "xy" and "yy" are both length-2 combinations of "xyy" , but "yx" is not. If there is more than one way to generate the same subsequence, only one will be returned.

For example, "xyyy" has three different ways to generate "xy" depending on whether the first, second, or third "y" is selected. However, since all are identical, only one will be chosen. Which of the three will be taken is an implementation detail that is not defined.

• returns
  • An Iterator which traverses the possible n-element combinations of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike

Example:

"abbbc".combinations(2) = Iterator(ab, ac, bb, bc)

(added by implicit convertion: scala.Predef.genericArrayOps)

def containsSlice[B](that: GenSeq[B]): Boolean

Tests whether this mutable indexed sequence contains a given sequence as a slice.

• that
  • the sequence to test
• returns
  • true if this mutable indexed sequence contains a slice with the same elements as that , otherwise false .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def contains[A1 >: A](elem: A1): Boolean

Tests whether this mutable indexed sequence contains a given value as an element.

• elem
  • the element to test.
• returns
  • true if this mutable indexed sequence has an element that is equal (as determined by == ) to elem , false otherwise.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def copyToArray[B >: A](xs: Array[B]): Unit

[use case]

Copies the elements of this array to an array. Fills the given array xs with values of this array. Copying will stop once either the end of the current array is reached, or the end of the target array is reached.

• xs
  • the array to fill.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def copyToArray[B >: A](xs: Array[B], start: Int): Unit

[use case]

Copies the elements of this array to an array. Fills the given array xs with values of this array, beginning at index start . Copying will stop once either the end of the current array is reached, or the end of the target array is reached.

• xs
  • the array to fill.
• start
  • the starting index.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def copyToArray[U >: T](xs: Array[U], start: Int, len: Int): Unit

[use case]

Copies the elements of this array to an array. Fills the given array xs with at most len elements of this array, starting at position start . Copying will stop once either the end of the current array is reached, or the end of the target array is reached, or len elements have been copied.

• xs
  • the array to fill.
• start
  • the starting index.
• len
  • the maximal number of elements to copy.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • ArrayOps → IndexedSeqOptimized → IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def copyToBuffer[B >: A](dest: Buffer[B]): Unit

Copies all elements of this mutable indexed sequence to a buffer.

• dest
  • The buffer to which elements are copied.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def corresponds[B](that: GenSeq[B])(p: (T, B) ⇒ Boolean): Boolean

Tests whether every element of this mutable indexed sequence 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 and p(x, y) is true for all corresponding elements x of this mutable indexed sequence and y of that , otherwise false .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def count(p: (T) ⇒ Boolean): Int

Counts the number of elements in the mutable indexed sequence which satisfy a predicate.

• p
  • the predicate used to test elements.
• returns
  • the number of elements satisfying the predicate p .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def deep: collection.IndexedSeq[Any]

Creates a possible nested IndexedSeq which consists of all the elements of this array. If the elements are arrays themselves, the deep transformation is applied recursively to them. The stringPrefix of the IndexedSeq is “Array”, hence the IndexedSeq prints like an array with all its elements shown, and the same recursively for any subarrays.

Example:

Array(Array(1, 2), Array(3, 4)).deep.toString

prints: Array(Array(1, 2), Array(3, 4))

• returns
  • An possibly nested indexed sequence of consisting of all the elements of the array.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • ArrayLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def diff[B >: A](that: GenSeq[B]): Array[T]

[use case]

Computes the multiset difference between this array and another sequence.

• that
  • the sequence of elements to remove
• returns
  • a new array which contains all elements of this array except some of occurrences of elements that also appear in that . If an element value x appears n times in that , then the first n occurrences of x will not form part of the result, but any following occurrences will.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def distinct: Array[T]

Builds a new mutable indexed sequence from this mutable indexed sequence without any duplicate elements.

• returns
  • A new mutable indexed sequence which contains the first occurrence of every element of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def drop(n: Int): Array[T]

Selects all elements except first n ones.

• n
  • the number of elements to drop from this mutable indexed sequence.
• returns
  • a mutable indexed sequence consisting of all elements of this mutable indexed sequence except the first n ones, or else the empty mutable indexed sequence, if this mutable indexed sequence has less than n elements.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → IterableLike → TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def dropRight(n: Int): Array[T]

Selects all elements except last n ones.

• n
  • The number of elements to take
• returns
  • a mutable indexed sequence consisting of all elements of this mutable indexed sequence except the last n ones, or else the empty mutable indexed sequence, if this mutable indexed sequence has less than n elements.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → IterableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def dropWhile(p: (T) ⇒ Boolean): Array[T]

Drops longest prefix of elements that satisfy a predicate.

• returns
  • the longest suffix of this mutable indexed sequence whose first element does not satisfy the predicate p .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def endsWith[B](that: GenSeq[B]): Boolean

Tests whether this mutable indexed sequence ends with the given sequence.

• that
  • the sequence to test
• returns
  • true if this mutable indexed sequence has that as a suffix, false otherwise.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def exists(p: (T) ⇒ Boolean): Boolean

Tests whether a predicate holds for at least one element of this mutable indexed sequence.

• p
  • the predicate used to test elements.
• returns
  • false if this mutable indexed sequence is empty, otherwise true if the given predicate p holds for some of the elements of this mutable indexed sequence, otherwise false
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def filter(p: (T) ⇒ Boolean): Array[T]

Selects all elements of this mutable indexed sequence which satisfy a predicate.

• p
  • the predicate used to test elements.
• returns
  • a new mutable indexed sequence consisting of all elements of this mutable indexed sequence that satisfy the given predicate p . The order of the elements is preserved.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def filterNot(p: (T) ⇒ Boolean): Array[T]

Selects all elements of this mutable indexed sequence which do not satisfy a predicate.

• p
  • the predicate used to test elements.
• returns
  • a new mutable indexed sequence consisting of all elements of this mutable indexed sequence that do not satisfy the given predicate p . The order of the elements is preserved.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def find(p: (T) ⇒ Boolean): Option[T]

Finds the first element of the mutable indexed sequence satisfying a predicate, if any.

• p
  • the predicate used to test elements.
• returns
  • an option value containing the first element in the mutable indexed sequence that satisfies p , or None if none exists.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def flatMap[B, That](f: (T) ⇒ GenTraversableOnce[B])(implicit bf: CanBuildFrom[Array[T], B, That]): That

[use case]

Builds a new collection by applying a function to all elements of this array 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 array. 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 => 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 array resulting from applying the given collection-valued function f to each element of this array and concatenating the results.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → GenTraversableLike → FilterMonadic

(added by implicit convertion: scala.Predef.genericArrayOps)

def flatten[U](implicit asTrav: (T) ⇒ collection.Traversable[U], m: ClassTag[U]): Array[U]

Flattens a two-dimensional array by concatenating all its rows into a single array.

• U
  • Type of row elements.
• asTrav
  • A function that converts elements of this array to rows - arrays of type U .
• returns
  • An array obtained by concatenating rows of this array.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • ArrayOps

(added by implicit convertion: scala.Predef.genericArrayOps)

def foldLeft[B](z: B)(op: (B, T) ⇒ B): B

Applies a binary operator to a start value and all elements of this mutable indexed sequence, going left to right.

• B
  • the result type of the binary operator.
• z
  • the start value.
• op
  • the binary operator.
• returns
  • the result of inserting op between consecutive elements of this mutable indexed sequence, going left to right with the start value z on the left:

    op(...op(z, x_1), x_2, ..., x_n)
    

where `x1, ..., xn` are the elements of this mutable indexed sequence.
Returns `z` if this mutable indexed sequence is empty.

• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def foldRight[B](z: B)(op: (T, B) ⇒ B): B

Applies a binary operator to all elements of this mutable indexed sequence and a start value, going right to left.

• B
  • the result type of the binary operator.
• z
  • the start value.
• op
  • the binary operator.
• returns
  • the result of inserting op between consecutive elements of this mutable indexed sequence, going right to left with the start value z on the right:

    op(x_1, op(x_2, ... op(x_n, z)...))
    

where `x1, ..., xn` are the elements of this mutable indexed sequence.
Returns `z` if this mutable indexed sequence is empty.

• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → IterableLike → TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def fold[A1 >: A](z: A1)(op: (A1, A1) ⇒ A1): A1

Folds the elements of this mutable indexed sequence using the specified associative binary operator.

The order in which operations are performed on elements is unspecified and may be nondeterministic.

• A1
  • a type parameter for the binary operator, a supertype of A .
• z
  • a neutral element for the fold operation; may be added to the result an arbitrary number of times, and must not change the result (e.g., Nil for list concatenation, 0 for addition, or 1 for multiplication).
• op
  • a binary operator that must be associative.
• returns
  • the result of applying the fold operator op between all the elements and z , or z if this mutable indexed sequence is empty.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def forall(p: (T) ⇒ Boolean): Boolean

Tests whether a predicate holds for all elements of this mutable indexed sequence.

• p
  • the predicate used to test elements.
• returns
  • true if this mutable indexed sequence is empty or the given predicate p holds for all elements of this mutable indexed sequence, otherwise false .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def foreach[U](f: (T) ⇒ U): Unit

[use case]

Applies a function f to all elements of this array.

Note: this method underlies the implementation of most other bulk operations. Subclasses should re-implement this method if a more efficient implementation exists.

• f
  • the function that is applied for its side-effect to every element. The result of function f is discarded.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → IterableLike → TraversableLike → GenTraversableLike → TraversableOnce → GenTraversableOnce → FilterMonadic

(added by implicit convertion: scala.Predef.genericArrayOps)

def groupBy[K](f: (T) ⇒ K): Map[K, Array[T]]

Partitions this mutable indexed sequence into a map of mutable indexed sequences according to some discriminator function.

Note: this method is not re-implemented by views. This means when applied to a view it will always force the view and return a new mutable indexed sequence.

• K
  • the type of keys returned by the discriminator function.
• f
  • the discriminator function.
• returns
  • A map from keys to mutable indexed sequences 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 mutable indexed sequence of those
elements `x` for which `f(x)` equals `k` .

• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def grouped(size: Int): collection.Iterator[Array[T]]

Partitions elements in fixed size mutable indexed sequences.

• size
  • the number of elements per group
• returns
  • An iterator producing mutable indexed sequences of size size , except the last will be less than size size if the elements don’t divide evenly.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IterableLike
• See also
  • scala.collection.Iterator, method grouped

(added by implicit convertion: scala.Predef.genericArrayOps)

def head: T

Selects the first element of this mutable indexed sequence.

• returns
  • the first element of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → IterableLike → TraversableLike → GenTraversableLike
• Exceptions thrown
  • NoSuchElementException if the mutable indexed sequence is empty.

(added by implicit convertion: scala.Predef.genericArrayOps)

def headOption: Option[T]

Optionally selects the first element.

• returns
  • the first element of this mutable indexed sequence if it is nonempty, None if it is empty.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def indexOf[B >: A](elem: B): Int

[use case]

Finds index of first occurrence of some value in this array.

• elem
  • the element value to search for.
• returns
  • the index of the first element of this array that is equal (as determined by == ) to elem , or -1 , if none exists.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def indexOf[B >: A](elem: B, from: Int): Int

[use case]

Finds index of first occurrence of some value in this array after or at some start index.

• elem
  • the element value to search for.
• from
  • the start index
• returns
  • the index >= from of the first element of this array that is equal (as determined by == ) to elem , or -1 , if none exists.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def indexOfSlice[B >: A](that: GenSeq[B]): Int

Finds first index where this mutable indexed sequence contains a given sequence as a slice.

• that
  • the sequence to test
• returns
  • the first index such that the elements of this mutable indexed sequence starting at this index match the elements of sequence that , or -1 of no such subsequence exists.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def indexOfSlice[B >: A](that: GenSeq[B], from: Int): Int

Finds first index after or at a start index where this mutable indexed sequence 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 mutable indexed sequence starting at this index match the elements of sequence that , or -1 of no such subsequence exists.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def indexWhere(p: (T) ⇒ Boolean): Int

Finds index of first element satisfying some predicate.

• p
  • the predicate used to test elements.
• returns
  • the index of the first element of this mutable indexed sequence that satisfies the predicate p , or -1 , if none exists.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def indexWhere(p: (T) ⇒ Boolean, from: Int): Int

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 mutable indexed sequence that satisfies the predicate p , or -1 , if none exists.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def indices: collection.immutable.Range

Produces the range of all indices of this sequence.

• returns
  • a Range value from 0 to one less than the length of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def init: Array[T]

Selects all elements except the last.

• returns
  • a mutable indexed sequence consisting of all elements of this mutable indexed sequence except the last one.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → TraversableLike → GenTraversableLike
• Exceptions thrown
  • UnsupportedOperationException if the mutable indexed sequence is empty.

(added by implicit convertion: scala.Predef.genericArrayOps)

def inits: collection.Iterator[Array[T]]

Iterates over the inits of this mutable indexed sequence. The first value will be this mutable indexed sequence and the final one will be an empty mutable indexed sequence, with the intervening values the results of successive applications of init .

• returns
  • an iterator over all the inits of this mutable indexed sequence
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike

Example:

List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)

(added by implicit convertion: scala.Predef.genericArrayOps)

def intersect[B >: A](that: GenSeq[B]): Array[T]

[use case]

Computes the multiset intersection between this array and another sequence.

• that
  • the sequence of elements to intersect with.
• returns
  • a new array which contains all elements of this array which also appear in that . If an element value x appears n times in that , then the first n occurrences of x will be retained in the result, but any following occurrences will be omitted.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def isDefinedAt(idx: Int): Boolean

Tests whether this mutable indexed sequence contains given index.

The implementations of methods apply and isDefinedAt turn a Seq[A] into a PartialFunction[Int, A] .

• idx
  • the index to test
• returns
  • true if this mutable indexed sequence contains an element at position idx , false otherwise.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def iterator: collection.Iterator[T]

Creates a new iterator over all elements contained in this iterable object.

• returns
  • the new iterator
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqLike → IterableLike → GenIterableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def last: T

Selects the last element.

• returns
  • The last element of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → TraversableLike → GenTraversableLike
• Exceptions thrown
  • NoSuchElementException If the mutable indexed sequence is empty.

(added by implicit convertion: scala.Predef.genericArrayOps)

def lastIndexOf[B >: A](elem: B): Int

[use case]

Finds index of last occurrence of some value in this array.

• elem
  • the element value to search for.
• returns
  • the index of the last element of this array that is equal (as determined by == ) to elem , or -1 , if none exists.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def lastIndexOf[B >: A](elem: B, end: Int): Int

[use case]

Finds index of last occurrence of some value in this array before or at a given end index.

• elem
  • the element value to search for.
• end
  • the end index.
• returns
  • the index <= end of the last element of this array that is equal (as determined by == ) to elem , or -1 , if none exists.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def lastIndexOfSlice[B >: A](that: GenSeq[B]): Int

Finds last index where this mutable indexed sequence contains a given sequence as a slice.

• that
  • the sequence to test
• returns
  • the last index such that the elements of this mutable indexed sequence starting a this index match the elements of sequence that , or -1 of no such subsequence exists.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def lastIndexOfSlice[B >: A](that: GenSeq[B], end: Int): Int

Finds last index before or at a given end index where this mutable indexed sequence 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 mutable indexed sequence starting at this index match the elements of sequence that , or -1 of no such subsequence exists.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def lastIndexWhere(p: (T) ⇒ Boolean): Int

Finds index of last element satisfying some predicate.

• p
  • the predicate used to test elements.
• returns
  • the index of the last element of this mutable indexed sequence that satisfies the predicate p , or -1 , if none exists.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def lastIndexWhere(p: (T) ⇒ Boolean, end: Int): Int

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 mutable indexed sequence that satisfies the predicate p , or -1 , if none exists.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def lastOption: Option[T]

Optionally selects the last element.

• returns
  • the last element of this mutable indexed sequence$ if it is nonempty, None if it is empty.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def lengthCompare(len: Int): Int

Compares the length of this mutable indexed sequence to a test value.

• len
  • the test value that gets compared with the length.
• returns
  • A value x where

    x <  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 is `O(length min len)` instead of `O(length)` . The method should be
overwritten if computing `length` is cheap.

• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → SeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def map[B, That](f: (T) ⇒ B)(implicit bf: CanBuildFrom[Array[T], B, That]): That

[use case]

Builds a new collection by applying a function to all elements of this array.

• B
  • the element type of the returned collection.
• f
  • the function to apply to each element.
• returns
  • a new array resulting from applying the given function f to each element of this array and collecting the results.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → GenTraversableLike → FilterMonadic

(added by implicit convertion: scala.Predef.genericArrayOps)

def maxBy[B](f: (T) ⇒ B)(implicit cmp: Ordering[B]): T

[use case]

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 array with the largest value measured by function f.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def minBy[B](f: (T) ⇒ B)(implicit cmp: Ordering[B]): T

[use case]

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 array with the smallest value measured by function f.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def mkString(sep: String): String

Displays all elements of this mutable indexed sequence in a string using a separator string.

• sep
  • the separator string.
• returns
  • a string representation of this mutable indexed sequence. In the resulting string the string representations (w.r.t. the method toString ) of all elements of this mutable indexed sequence are separated by the string sep .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

Example:

List(1, 2, 3).mkString("|") = "1|2|3"

(added by implicit convertion: scala.Predef.genericArrayOps)

def mkString(start: String, sep: String, end: String): String

Displays all elements of this mutable indexed sequence in a string using start, end, and separator strings.

• start
  • the starting string.
• sep
  • the separator string.
• end
  • the ending string.
• returns
  • a string representation of this mutable indexed sequence. The resulting string begins with the string start and ends with the string end . Inside, the string representations (w.r.t. the method toString ) of all elements of this mutable indexed sequence are separated by the string sep .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

Example:

List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"

(added by implicit convertion: scala.Predef.genericArrayOps)

def padTo[B >: A, That](len: Int, elem: B)(implicit bf: CanBuildFrom[Array[T], B, That]): That

[use case]

A copy of this array with an element value appended until a given target length is reached.

• len
  • the target length
• elem
  • the padding value
• returns
  • a new array consisting of all elements of this array followed by the minimal number of occurrences of elem so that the resulting array has a length of at least len .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def par: ParArray[T]

Returns a parallel implementation of this collection.

For most collection types, this method creates a new parallel collection by copying all the elements. For these collection, par takes linear time. Mutable collections in this category do not produce a mutable parallel collection that has the same underlying dataset, so changes in one collection will not be reflected in the other one.

Specific collections (e.g. ParArray or mutable.ParHashMap ) override this default behaviour by creating a parallel collection which shares the same underlying dataset. For these collections, par takes constant or sublinear time.

All parallel collections return a reference to themselves.

• returns
  • a parallel implementation of this collection
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • ArrayOps → CustomParallelizable → Parallelizable

(added by implicit convertion: scala.Predef.genericArrayOps)

def partition(p: (T) ⇒ Boolean): (Array[T], Array[T])

Partitions this mutable indexed sequence in two mutable indexed sequences according to a predicate.

• p
  • the predicate on which to partition.
• returns
  • a pair of mutable indexed sequences: the first mutable indexed sequence consists of all elements that satisfy the predicate p and the second mutable indexed sequence consists of all elements that don’t. The relative order of the elements in the resulting mutable indexed sequences is the same as in the original mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def patch[B >: A, That](from: Int, patch: GenSeq[B], replaced: Int)(implicit bf: CanBuildFrom[Array[T], B, That]): That

[use case]

Produces a new array where a slice of elements in this array is replaced by another sequence.

• from
  • the index of the first replaced element
• replaced
  • the number of elements to drop in the original array
• returns
  • a new array consisting of all elements of this array except that replaced elements starting from from are replaced by patch .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def permutations: collection.Iterator[Array[T]]

Iterates over distinct permutations.

• returns
  • An Iterator which traverses the distinct permutations of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike

Example:

"abb".permutations = Iterator(abb, bab, bba)

(added by implicit convertion: scala.Predef.genericArrayOps)

def prefixLength(p: (T) ⇒ Boolean): Int

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 mutable indexed sequence such that every element of the segment satisfies the predicate p .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def reduceLeftOption[B >: A](op: (B, T) ⇒ B): Option[B]

Optionally applies a binary operator to all elements of this mutable indexed sequence, going left to right.

• B
  • the result type of the binary operator.
• op
  • the binary operator.
• returns
  • an option value containing the result of reduceLeft(op) if this mutable indexed sequence is nonempty, None otherwise.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def reduceLeft[B >: A](op: (B, T) ⇒ B): B

Applies a binary operator to all elements of this mutable indexed sequence, going left to right.

• B
  • the result type of the binary operator.
• op
  • the binary operator.
• returns
  • the result of inserting op between consecutive elements of this mutable indexed sequence, going left to right:

    op( op( ... op(x_1, x_2) ..., x_{n-1}), x_n)
    

where `x1, ..., xn` are the elements of this mutable indexed sequence.

• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → TraversableOnce
• Exceptions thrown
  • UnsupportedOperationException if this mutable indexed sequence is empty.

(added by implicit convertion: scala.Predef.genericArrayOps)

def reduceOption[A1 >: A](op: (A1, A1) ⇒ A1): Option[A1]

Reduces the elements of this mutable indexed sequence, if any, using the specified associative binary operator.

The order in which operations are performed on elements is unspecified and may be nondeterministic.

• A1
  • A type parameter for the binary operator, a supertype of A .
• op
  • A binary operator that must be associative.
• returns
  • An option value containing result of applying reduce operator op between all the elements if the collection is nonempty, and None otherwise.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def reduceRightOption[B >: A](op: (T, B) ⇒ B): Option[B]

Optionally applies a binary operator to all elements of this mutable indexed sequence, going right to left.

• B
  • the result type of the binary operator.
• op
  • the binary operator.
• returns
  • an option value containing the result of reduceRight(op) if this mutable indexed sequence is nonempty, None otherwise.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def reduceRight[B >: A](op: (T, B) ⇒ B): B

Applies a binary operator to all elements of this mutable indexed sequence, going right to left.

• B
  • the result type of the binary operator.
• op
  • the binary operator.
• returns
  • the result of inserting op between consecutive elements of this mutable indexed sequence, going right to left:

    op(x_1, op(x_2, ..., op(x_{n-1}, x_n)...))
    

where `x1, ..., xn` are the elements of this mutable indexed sequence.

• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → IterableLike → TraversableOnce → GenTraversableOnce
• Exceptions thrown
  • UnsupportedOperationException if this mutable indexed sequence is empty.

(added by implicit convertion: scala.Predef.genericArrayOps)

def reduce[A1 >: A](op: (A1, A1) ⇒ A1): A1

Reduces the elements of this mutable indexed sequence using the specified associative binary operator.

The order in which operations are performed on elements is unspecified and may be nondeterministic.

• A1
  • A type parameter for the binary operator, a supertype of A .
• op
  • A binary operator that must be associative.
• returns
  • The result of applying reduce operator op between all the elements if the mutable indexed sequence is nonempty.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce
• Exceptions thrown
  • UnsupportedOperationException if this mutable indexed sequence is empty.

(added by implicit convertion: scala.Predef.genericArrayOps)

def repr: Array[T]

The collection of type mutable indexed sequence underlying this TraversableLike object. By default this is implemented as the TraversableLike object itself, but this can be overridden.

• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def reverse: Array[T]

Returns new mutable indexed sequence with elements in reversed order.

• returns
  • A new mutable indexed sequence with all elements of this mutable indexed sequence in reversed order.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def reverseIterator: collection.Iterator[T]

An iterator yielding elements in reversed order.

Note: xs.reverseIterator is the same as xs.reverse.iterator but might be more efficient.

• returns
  • an iterator yielding the elements of this mutable indexed sequence in reversed order
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → SeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def reverseMap[B, That](f: (T) ⇒ B)(implicit bf: CanBuildFrom[Array[T], B, That]): That

[use case]

Builds a new collection by applying a function to all elements of this array and collecting the results in reversed order.

Note: xs.reverseMap(f) is the same as xs.reverse.map(f) but might be more efficient.

• B
  • the element type of the returned collection.
• f
  • the function to apply to each element.
• returns
  • a new array resulting from applying the given function f to each element of this array and collecting the results in reversed order.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def sameElements[B >: A](that: GenIterable[B]): Boolean

[use case]

Checks if the other iterable collection contains the same elements in the same order as this array.

• that
  • the collection to compare with.
• returns
  • true , if both collections contain the same elements in the same order, false otherwise.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → IterableLike → GenIterableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def scanLeft[B, That](z: B)(op: (B, T) ⇒ B)(implicit bf: CanBuildFrom[Array[T], B, That]): That

Produces a collection containing cumulative results of applying the operator going left to right.

• B
  • the type of the elements in the resulting collection
• That
  • the actual type of the resulting collection
• z
  • the initial value
• op
  • the binary operator applied to the intermediate result and the element
• bf
  • an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type B .
• returns
  • collection with intermediate results
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def scanRight[B, That](z: B)(op: (T, B) ⇒ B)(implicit bf: CanBuildFrom[Array[T], B, That]): That

Produces a collection containing cumulative results of applying the operator going right to left. The head of the collection is the last cumulative result.

Example:

List(1, 2, 3, 4).scanRight(0)(_ + _) == List(10, 9, 7, 4, 0)

• B
  • the type of the elements in the resulting collection
• That
  • the actual type of the resulting collection
• z
  • the initial value
• op
  • the binary operator applied to the intermediate result and the element
• bf
  • an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type B .
• returns
  • collection with intermediate results
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → GenTraversableLike
• Annotations
  • @migration
• Migration
  • (Changed in version 2.9.0) The behavior of scanRight has changed. The previous behavior can be reproduced with scanRight.reverse.

(added by implicit convertion: scala.Predef.genericArrayOps)

def scan[B >: A, That](z: B)(op: (B, B) ⇒ B)(implicit cbf: CanBuildFrom[Array[T], B, That]): That

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
• That
  • type of the resulting collection
• z
  • neutral element for the operator op
• op
  • the associative operator for the scan
• cbf
  • combiner factory which provides a combiner
• returns
  • a new mutable indexed sequence containing the prefix scan of the elements in this mutable indexed sequence
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def segmentLength(p: (T) ⇒ Boolean, from: Int): Int

Computes length of longest segment 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 mutable indexed sequence starting from index from such that every element of the segment satisfies the predicate p .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def seq: collection.mutable.IndexedSeq[T]

A version of this collection with all of the operations implemented sequentially (i.e., in a single-threaded manner).

This method returns a reference to this collection. In parallel collections, it is redefined to return a sequential implementation of this collection. In both cases, it has O(1) complexity.

• returns
  • a sequential view of the collection.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • ArrayOps → IndexedSeqLike → GenSeqLike → Parallelizable → TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def slice(from: Int, until: Int): Array[T]

Selects an interval of elements. The returned collection is made up of all elements x which satisfy the invariant:

from <= indexOf(x) < until

• returns
  • a mutable indexed sequence containing the elements greater than or equal to index from extending up to (but not including) index until of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → IterableLike → TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def sliding(size: Int): collection.Iterator[Array[T]]

Groups elements in fixed size blocks by passing a “sliding window” over them (as opposed to partitioning them, as is done in grouped.) “Sliding window” step is 1 by default.

• size
  • the number of elements per group
• returns
  • An iterator producing mutable indexed sequences of size size , except the last and the only element will be truncated if there are fewer elements than size.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IterableLike
• See also
  • scala.collection.Iterator, method sliding

(added by implicit convertion: scala.Predef.genericArrayOps)

def sliding(size: Int, step: Int): collection.Iterator[Array[T]]

Groups elements in fixed size blocks by passing a “sliding window” over them (as opposed to partitioning them, as is done in grouped.)

• size
  • the number of elements per group
• step
  • the distance between the first elements of successive groups
• returns
  • An iterator producing mutable indexed sequences of size size , except the last and the only element will be truncated if there are fewer elements than size.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IterableLike
• See also
  • scala.collection.Iterator, method sliding

(added by implicit convertion: scala.Predef.genericArrayOps)

def sortBy[B](f: (T) ⇒ B)(implicit ord: math.Ordering[B]): Array[T]

Sorts this Array according to the Ordering which results from transforming an implicitly given Ordering with a transformation function.

• B
  • the target type of the transformation f , and the type where the ordering ord is defined.
• f
  • the transformation function mapping elements to some other domain B .
• ord
  • the ordering assumed on domain B .
• returns
  • a mutable indexed sequence consisting of the elements of this mutable indexed sequence sorted according to the ordering where x < y if ord.lt(f(x), f(y)) .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike
• See also
  • scala.math.Ordering

Example:

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)

(added by implicit convertion: scala.Predef.genericArrayOps)

def sortWith(lt: (T, T) ⇒ Boolean): Array[T]

Sorts this mutable indexed sequence according to a comparison function.

The sort is stable. That is, elements that are equal (as determined by lt ) appear in the same order in the sorted sequence as in the original.

• lt
  • the comparison function which tests whether its first argument precedes its second argument in the desired ordering.
• returns
  • a mutable indexed sequence consisting of the elements of this mutable indexed sequence sorted according to the comparison function lt .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike

Example:

List("Steve", "Tom", "John", "Bob").sortWith(_.compareTo(_) < 0) =
List("Bob", "John", "Steve", "Tom")

(added by implicit convertion: scala.Predef.genericArrayOps)

def sorted[B >: A](implicit ord: math.Ordering[B]): Array[T]

Sorts this mutable indexed sequence according to an Ordering.

The sort is stable. That is, elements that are equal (as determined by lt ) appear in the same order in the sorted sequence as in the original.

• ord
  • the ordering to be used to compare elements.
• returns
  • a mutable indexed sequence consisting of the elements of this mutable indexed sequence sorted according to the ordering ord .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike
• See also
  • scala.math.Ordering

(added by implicit convertion: scala.Predef.genericArrayOps)

def span(p: (T) ⇒ Boolean): (Array[T], Array[T])

Splits this mutable indexed sequence 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 predicate p does not cause any side-effects.

• returns
  • a pair consisting of the longest prefix of this mutable indexed sequence whose elements all satisfy p , and the rest of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def splitAt(n: Int): (Array[T], Array[T])

Splits this mutable indexed sequence into two 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 mutable indexed sequences consisting of the first n elements of this mutable indexed sequence, and the other elements.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def startsWith[B](that: GenSeq[B]): Boolean

Tests whether this mutable indexed sequence starts with the given sequence.

• that
  • the sequence to test
• returns
  • true if this collection has that as a prefix, false otherwise.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def startsWith[B](that: GenSeq[B], offset: Int): Boolean

Tests whether this mutable indexed sequence contains the given sequence at a given index.

Note : If the both the receiver object this and the argument that 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 sequence that is contained in this mutable indexed sequence at index offset , otherwise false .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def tail: Array[T]

Selects all elements except the first.

• returns
  • a mutable indexed sequence consisting of all elements of this mutable indexed sequence except the first one.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → TraversableLike → GenTraversableLike
• Exceptions thrown
  • UnsupportedOperationException if the mutable indexed sequence is empty.

(added by implicit convertion: scala.Predef.genericArrayOps)

def tails: collection.Iterator[Array[T]]

Iterates over the tails of this mutable indexed sequence. The first value will be this mutable indexed sequence and the final one will be an empty mutable indexed sequence, with the intervening values the results of successive applications of tail .

• returns
  • an iterator over all the tails of this mutable indexed sequence
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike

Example:

List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)

(added by implicit convertion: scala.Predef.genericArrayOps)

def take(n: Int): Array[T]

Selects first n elements.

• n
  • the number of elements to take from this mutable indexed sequence.
• returns
  • a mutable indexed sequence consisting only of the first n elements of this mutable indexed sequence, or else the whole mutable indexed sequence, if it has less than n elements.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → IterableLike → TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def takeRight(n: Int): Array[T]

Selects last n elements.

• n
  • the number of elements to take
• returns
  • a mutable indexed sequence consisting only of the last n elements of this mutable indexed sequence, or else the whole mutable indexed sequence, if it has less than n elements.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → IterableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def takeWhile(p: (T) ⇒ Boolean): Array[T]

Takes longest prefix of elements that satisfy a predicate.

• returns
  • the longest prefix of this mutable indexed sequence whose elements all satisfy the predicate p .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → IterableLike → TraversableLike → GenTraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def toBuffer[A1 >: A]: Buffer[A1]

Uses the contents of this mutable indexed sequence to create a new mutable buffer.

• returns
  • a buffer containing all elements of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqLike → TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def toIndexedSeq: collection.immutable.IndexedSeq[T]

Converts this mutable indexed sequence to an indexed sequence.

• returns
  • an indexed sequence containing all elements of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def toIterable: collection.Iterable[T]

Returns this mutable indexed sequence as an iterable collection.

A new collection will not be built; lazy collections will stay lazy.

• returns
  • an Iterable containing all elements of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IterableLike → TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def toIterator: collection.Iterator[T]

Returns an Iterator over the elements in this mutable indexed sequence. Produces the same result as iterator .

• returns
  • an Iterator containing all elements of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IterableLike → TraversableLike → GenTraversableOnce
• Annotations
  • @ deprecatedOverriding (message =…, since = “2.11.0”)

(added by implicit convertion: scala.Predef.genericArrayOps)

def toList: List[T]

Converts this mutable indexed sequence to a list.

• returns
  • a list containing all elements of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def toMap[T, U](implicit ev: <:<[T, (T, U)]): Map[T, U]

[use case]

Converts this array to a map. This method is unavailable unless the elements are members of Tuple2, each ((T, U)) becoming a key-value pair in the map. Duplicate keys will be overwritten by later keys: if this is an unordered collection, which key is in the resulting map is undefined.

• returns
  • a map of type immutable.Map[T, U] containing all key/value pairs of type (T, U) of this array.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def toSeq: collection.Seq[T]

Converts this mutable indexed sequence to a sequence.

A new collection will not be built; in particular, lazy sequences will stay lazy.

• returns
  • a sequence containing all elements of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike → GenSeqLike → TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def toSet[B >: A]: Set[B]

Converts this mutable indexed sequence to a set.

• returns
  • a set containing all elements of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def toStream: collection.immutable.Stream[T]

Converts this mutable indexed sequence to a stream.

• returns
  • a stream containing all elements of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IterableLike → TraversableLike → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def toTraversable: collection.Traversable[T]

Converts this mutable indexed sequence to an unspecified Traversable. Will return the same collection if this instance is already Traversable.

• returns
  • a Traversable containing all elements of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → TraversableOnce → GenTraversableOnce
• Annotations
  • @ deprecatedOverriding (message =…, since = “2.11.0”)

(added by implicit convertion: scala.Predef.genericArrayOps)

def toVector: Vector[T]

Converts this mutable indexed sequence to a Vector.

• returns
  • a vector containing all elements of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableOnce → GenTraversableOnce

(added by implicit convertion: scala.Predef.genericArrayOps)

def transpose[U](implicit asArray: (T) ⇒ Array[U]): Array[Array[U]]

Transposes a two dimensional array.

• U
  • Type of row elements.
• asArray
  • A function that converts elements of this array to rows - arrays of type U .
• returns
  • An array obtained by replacing elements of this arrays with rows the represent.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • ArrayOps

(added by implicit convertion: scala.Predef.genericArrayOps)

def union[B >: A, That](that: GenSeq[B])(implicit bf: CanBuildFrom[Array[T], B, That]): That

[use case]

Produces a new sequence which contains all elements of this array and also all elements of a given sequence. xs union ys is equivalent to xs ++ ys .

Another way to express this is that xs union ys computes the order-preserving multi-set union of xs and ys . union is hence a counter-part of diff and intersect which also work on multi-sets.

• that
  • the sequence to add.
• returns
  • a new array which contains all elements of this array followed by all elements of that .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def unzip3[T1, T2, T3](implicit asTriple: (T) ⇒ (T1, T2, T3), ct1: ClassTag[T1], ct2: ClassTag[T2], ct3: ClassTag[T3]): (Array[T1], Array[T2], Array[T3])

Converts an array of triples into three arrays, one containing the elements from each position of the triple.

• T1
  • the type of the first of three elements in the triple
• T2
  • the type of the second of three elements in the triple
• T3
  • the type of the third of three elements in the triple
• asTriple
  • an implicit conversion which asserts that the element type of this Array is a triple.
• ct1
  • a class tag for T1 type parameter that is required to create an instance of Array[T1]
• ct2
  • a class tag for T2 type parameter that is required to create an instance of Array[T2]
• ct3
  • a class tag for T3 type parameter that is required to create an instance of Array[T3]
• returns
  • a triple of Arrays, containing, respectively, the first, second, and third elements from each element triple of this Array.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • ArrayOps

(added by implicit convertion: scala.Predef.genericArrayOps)

def unzip[T1, T2](implicit asPair: (T) ⇒ (T1, T2), ct1: ClassTag[T1], ct2: ClassTag[T2]): (Array[T1], Array[T2])

Converts an array of pairs into an array of first elements and an array of second elements.

• T1
  • the type of the first half of the element pairs
• T2
  • the type of the second half of the element pairs
• asPair
  • an implicit conversion which asserts that the element type of this Array is a pair.
• ct1
  • a class tag for T1 type parameter that is required to create an instance of Array[T1]
• ct2
  • a class tag for T2 type parameter that is required to create an instance of Array[T2]
• returns
  • a pair of Arrays, containing, respectively, the first and second half of each element pair of this Array.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • ArrayOps

(added by implicit convertion: scala.Predef.genericArrayOps)

def updated[B >: A, That](index: Int, elem: B)(implicit bf: CanBuildFrom[Array[T], B, That]): That

[use case]

A copy of this array with one single replaced element.

• index
  • the position of the replacement
• elem
  • the replacing element
• returns
  • a copy of this array with the element at position index replaced by elem .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • SeqLike → GenSeqLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def view(from: Int, until: Int): IndexedSeqView[T, Array[T]]

A sub-sequence view starting at index from and extending up to (but not including) index until .

• from
  • The index of the first element of the slice
• until
  • The index of the element following the slice
• returns
  • a non-strict view of a slice of this mutable indexed sequence, starting at index from and extending up to (but not including) index until .@note The difference between view and slice is that view produces a view of the current sequence, whereas slice produces a new sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqLike → SeqLike → IterableLike → TraversableLike
• Note
  • view(from, to) is equivalent to view.slice(from, to)

(added by implicit convertion: scala.Predef.genericArrayOps)

def view: IndexedSeqView[T, Array[T]]

Creates a view of this iterable @see Iterable.View

• returns
  • a non-strict view of this mutable indexed sequence.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqLike → SeqLike → IterableLike → TraversableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def withFilter(p: (T) ⇒ Boolean): FilterMonadic[T, Array[T]]

Creates a non-strict filter of this mutable indexed sequence.

Note: the difference between c filter p and c withFilter p is that the former creates a new collection, whereas the latter only restricts the domain of subsequent map , flatMap , foreach , and withFilter operations.

• p
  • the predicate used to test elements.
• returns
  • an object of class WithFilter , which supports map , flatMap , foreach , and withFilter operations. All these operations apply to those elements of this mutable indexed sequence which satisfy the predicate p .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • TraversableLike → FilterMonadic

(added by implicit convertion: scala.Predef.genericArrayOps)

def zipAll[B, A1 >: A, That](that: GenIterable[B], thisElem: A1, thatElem: B)(implicit bf: CanBuildFrom[Array[T], (A1, B), That]): That

[use case]

Returns a array formed from this array 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.

• B
  • the type of the second half of the returned pairs
• that
  • The iterable providing the second half of each result pair
• thisElem
  • the element to be used to fill up the result if this array is shorter than that .
• thatElem
  • the element to be used to fill up the result if that is shorter than this array.
• returns
  • a new array containing pairs consisting of corresponding elements of this array and that . The length of the returned collection is the maximum of the lengths of this array and that . If this array is shorter than that , thisElem values are used to pad the result. If that is shorter than this array, thatElem values are used to pad the result.
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IterableLike → GenIterableLike

(added by implicit convertion: scala.Predef.genericArrayOps)

def zip[A1 >: A, B, That](that: GenIterable[B])(implicit bf: CanBuildFrom[Array[T], (A1, B), That]): That

[use case]

Returns a array formed from this array 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 array containing pairs consisting of corresponding elements of this array and that . The length of the returned collection is the minimum of the lengths of this array and that .
• Implicit information
  • This member is added by an implicit conversion from Array [T] to ArrayOps [T] performed by method genericArrayOps in scala.Predef.
• Definition Classes
  • IndexedSeqOptimized → IterableLike → GenIterableLike (added by implicit convertion: scala.Predef.genericArrayOps)

Full Source:

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2002-2013, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

package scala

import scala.collection.generic._
import scala.collection.{ mutable, immutable }
import mutable.{ ArrayBuilder, ArraySeq }
import scala.compat.Platform.arraycopy
import scala.reflect.ClassTag
import scala.runtime.ScalaRunTime.{ array_apply, array_update }

/** Contains a fallback builder for arrays when the element type
 *  does not have a class tag. In that case a generic array is built.
 */
class FallbackArrayBuilding {

  /** A builder factory that generates a generic array.
   *  Called instead of `Array.newBuilder` if the element type of an array
   *  does not have a class tag. Note that fallbackBuilder factory
   *  needs an implicit parameter (otherwise it would not be dominated in
   *  implicit search by `Array.canBuildFrom`). We make sure that
   *  implicit search is always successful.
   */
  implicit def fallbackCanBuildFrom[T](implicit m: DummyImplicit): CanBuildFrom[Array[_], T, ArraySeq[T]] =
    new CanBuildFrom[Array[_], T, ArraySeq[T]] {
      def apply(from: Array[_]) = ArraySeq.newBuilder[T]
      def apply() = ArraySeq.newBuilder[T]
    }
}

/** 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)`.
 *
 *  @author Martin Odersky
 *  @version 1.0
 */
object Array extends FallbackArrayBuilding {
  val emptyBooleanArray = new Array[Boolean](0)
  val emptyByteArray    = new Array[Byte](0)
  val emptyCharArray    = new Array[Char](0)
  val emptyDoubleArray  = new Array[Double](0)
  val emptyFloatArray   = new Array[Float](0)
  val emptyIntArray     = new Array[Int](0)
  val emptyLongArray    = new Array[Long](0)
  val emptyShortArray   = new Array[Short](0)
  val emptyObjectArray  = new Array[Object](0)

  implicit def canBuildFrom[T](implicit t: ClassTag[T]): CanBuildFrom[Array[_], T, Array[T]] =
    new CanBuildFrom[Array[_], T, Array[T]] {
      def apply(from: Array[_]) = ArrayBuilder.make[T]()(t)
      def apply() = ArrayBuilder.make[T]()(t)
    }

  /**
   * Returns a new [[scala.collection.mutable.ArrayBuilder]].
   */
  def newBuilder[T](implicit t: ClassTag[T]): ArrayBuilder[T] = ArrayBuilder.make[T]()(t)

  private def slowcopy(src : AnyRef,
                       srcPos : Int,
                       dest : AnyRef,
                       destPos : Int,
                       length : Int) {
    var i = srcPos
    var j = destPos
    val srcUntil = srcPos + length
    while (i < srcUntil) {
      array_update(dest, j, array_apply(src, i))
      i += 1
      j += 1
    }
  }

  /** 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.
   *
   *  @param src the source array.
   *  @param srcPos  starting position in the source array.
   *  @param dest destination array.
   *  @param destPos starting position in the destination array.
   *  @param length the number of array elements to be copied.
   *
   *  @see `java.lang.System#arraycopy`
   */
  def copy(src: AnyRef, srcPos: Int, dest: AnyRef, destPos: Int, length: Int) {
    val srcClass = src.getClass
    if (srcClass.isArray && dest.getClass.isAssignableFrom(srcClass))
      arraycopy(src, srcPos, dest, destPos, length)
    else
      slowcopy(src, srcPos, dest, destPos, length)
  }

  /** Returns an array of length 0 */
  def empty[T: ClassTag]: Array[T] = new Array[T](0)

  /** Creates an array with given elements.
   *
   *  @param xs the elements to put in the array
   *  @return an array containing all elements from xs.
   */
  // Subject to a compiler optimization in Cleanup.
  // Array(e0, ..., en) is translated to { val a = new Array(3); a(i) = ei; a }
  def apply[T: ClassTag](xs: T*): Array[T] = {
    val array = new Array[T](xs.length)
    var i = 0
    for (x <- xs.iterator) { array(i) = x; i += 1 }
    array
  }

  /** Creates an array of `Boolean` objects */
  // Subject to a compiler optimization in Cleanup, see above.
  def apply(x: Boolean, xs: Boolean*): Array[Boolean] = {
    val array = new Array[Boolean](xs.length + 1)
    array(0) = x
    var i = 1
    for (x <- xs.iterator) { array(i) = x; i += 1 }
    array
  }

  /** Creates an array of `Byte` objects */
  // Subject to a compiler optimization in Cleanup, see above.
  def apply(x: Byte, xs: Byte*): Array[Byte] = {
    val array = new Array[Byte](xs.length + 1)
    array(0) = x
    var i = 1
    for (x <- xs.iterator) { array(i) = x; i += 1 }
    array
  }

  /** Creates an array of `Short` objects */
  // Subject to a compiler optimization in Cleanup, see above.
  def apply(x: Short, xs: Short*): Array[Short] = {
    val array = new Array[Short](xs.length + 1)
    array(0) = x
    var i = 1
    for (x <- xs.iterator) { array(i) = x; i += 1 }
    array
  }

  /** Creates an array of `Char` objects */
  // Subject to a compiler optimization in Cleanup, see above.
  def apply(x: Char, xs: Char*): Array[Char] = {
    val array = new Array[Char](xs.length + 1)
    array(0) = x
    var i = 1
    for (x <- xs.iterator) { array(i) = x; i += 1 }
    array
  }

  /** Creates an array of `Int` objects */
  // Subject to a compiler optimization in Cleanup, see above.
  def apply(x: Int, xs: Int*): Array[Int] = {
    val array = new Array[Int](xs.length + 1)
    array(0) = x
    var i = 1
    for (x <- xs.iterator) { array(i) = x; i += 1 }
    array
  }

  /** Creates an array of `Long` objects */
  // Subject to a compiler optimization in Cleanup, see above.
  def apply(x: Long, xs: Long*): Array[Long] = {
    val array = new Array[Long](xs.length + 1)
    array(0) = x
    var i = 1
    for (x <- xs.iterator) { array(i) = x; i += 1 }
    array
  }

  /** Creates an array of `Float` objects */
  // Subject to a compiler optimization in Cleanup, see above.
  def apply(x: Float, xs: Float*): Array[Float] = {
    val array = new Array[Float](xs.length + 1)
    array(0) = x
    var i = 1
    for (x <- xs.iterator) { array(i) = x; i += 1 }
    array
  }

  /** Creates an array of `Double` objects */
  // Subject to a compiler optimization in Cleanup, see above.
  def apply(x: Double, xs: Double*): Array[Double] = {
    val array = new Array[Double](xs.length + 1)
    array(0) = x
    var i = 1
    for (x <- xs.iterator) { array(i) = x; i += 1 }
    array
  }

  /** Creates an array of `Unit` objects */
  def apply(x: Unit, xs: Unit*): Array[Unit] = {
    val array = new Array[Unit](xs.length + 1)
    array(0) = x
    var i = 1
    for (x <- xs.iterator) { array(i) = x; i += 1 }
    array
  }

  /** Creates array with given dimensions */
  def ofDim[T: ClassTag](n1: Int): Array[T] =
    new Array[T](n1)
  /** Creates a 2-dimensional array */
  def ofDim[T: ClassTag](n1: Int, n2: Int): Array[Array[T]] = {
    val arr: Array[Array[T]] = (new Array[Array[T]](n1): Array[Array[T]])
    for (i <- 0 until n1) arr(i) = new Array[T](n2)
    arr
    // tabulate(n1)(_ => ofDim[T](n2))
  }
  /** Creates a 3-dimensional array */
  def ofDim[T: ClassTag](n1: Int, n2: Int, n3: Int): Array[Array[Array[T]]] =
    tabulate(n1)(_ => ofDim[T](n2, n3))
  /** Creates a 4-dimensional array */
  def ofDim[T: ClassTag](n1: Int, n2: Int, n3: Int, n4: Int): Array[Array[Array[Array[T]]]] =
    tabulate(n1)(_ => ofDim[T](n2, n3, n4))
  /** Creates a 5-dimensional array */
  def ofDim[T: ClassTag](n1: Int, n2: Int, n3: Int, n4: Int, n5: Int): Array[Array[Array[Array[Array[T]]]]] =
    tabulate(n1)(_ => ofDim[T](n2, n3, n4, n5))

  /** Concatenates all arrays into a single array.
   *
   *  @param xss the given arrays
   *  @return   the array created from concatenating `xss`
   */
  def concat[T: ClassTag](xss: Array[T]*): Array[T] = {
    val b = newBuilder[T]
    b.sizeHint(xss.map(_.length).sum)
    for (xs <- xss) b ++= xs
    b.result()
  }

  /** 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)
   *  }}}
   *
   *  @param   n  the number of elements desired
   *  @param   elem the element computation
   *  @return an Array of size n, where each element contains the result of computing
   *  `elem`.
   */
  def fill[T: ClassTag](n: Int)(elem: => T): Array[T] = {
    val b = newBuilder[T]
    b.sizeHint(n)
    var i = 0
    while (i < n) {
      b += elem
      i += 1
    }
    b.result()
  }

  /** Returns a two-dimensional array that contains the results of some element
   *  computation a number of times.
   *
   *  @param   n1  the number of elements in the 1st dimension
   *  @param   n2  the number of elements in the 2nd dimension
   *  @param   elem the element computation
   */
  def fill[T: ClassTag](n1: Int, n2: Int)(elem: => T): Array[Array[T]] =
    tabulate(n1)(_ => fill(n2)(elem))

  /** Returns a three-dimensional array that contains the results of some element
   *  computation a number of times.
   *
   *  @param   n1  the number of elements in the 1st dimension
   *  @param   n2  the number of elements in the 2nd dimension
   *  @param   n3  the number of elements in the 3nd dimension
   *  @param   elem the element computation
   */
  def fill[T: ClassTag](n1: Int, n2: Int, n3: Int)(elem: => T): Array[Array[Array[T]]] =
    tabulate(n1)(_ => fill(n2, n3)(elem))

  /** Returns a four-dimensional array that contains the results of some element
   *  computation a number of times.
   *
   *  @param   n1  the number of elements in the 1st dimension
   *  @param   n2  the number of elements in the 2nd dimension
   *  @param   n3  the number of elements in the 3nd dimension
   *  @param   n4  the number of elements in the 4th dimension
   *  @param   elem the element computation
   */
  def fill[T: ClassTag](n1: Int, n2: Int, n3: Int, n4: Int)(elem: => T): Array[Array[Array[Array[T]]]] =
    tabulate(n1)(_ => fill(n2, n3, n4)(elem))

  /** Returns a five-dimensional array that contains the results of some element
   *  computation a number of times.
   *
   *  @param   n1  the number of elements in the 1st dimension
   *  @param   n2  the number of elements in the 2nd dimension
   *  @param   n3  the number of elements in the 3nd dimension
   *  @param   n4  the number of elements in the 4th dimension
   *  @param   n5  the number of elements in the 5th dimension
   *  @param   elem the element computation
   */
  def fill[T: ClassTag](n1: Int, n2: Int, n3: Int, n4: Int, n5: Int)(elem: => T): Array[Array[Array[Array[Array[T]]]]] =
    tabulate(n1)(_ => fill(n2, n3, n4, n5)(elem))

  /** Returns an array containing values of a given function over a range of integer
   *  values starting from 0.
   *
   *  @param  n   The number of elements in the array
   *  @param  f   The function computing element values
   *  @return A traversable consisting of elements `f(0),f(1), ..., f(n - 1)`
   */
  def tabulate[T: ClassTag](n: Int)(f: Int => T): Array[T] = {
    val b = newBuilder[T]
    b.sizeHint(n)
    var i = 0
    while (i < n) {
      b += f(i)
      i += 1
    }
    b.result()
  }

  /** Returns a two-dimensional array containing values of a given function
   *  over ranges of integer values starting from `0`.
   *
   *  @param   n1  the number of elements in the 1st dimension
   *  @param   n2  the number of elements in the 2nd dimension
   *  @param   f   The function computing element values
   */
  def tabulate[T: ClassTag](n1: Int, n2: Int)(f: (Int, Int) => T): Array[Array[T]] =
    tabulate(n1)(i1 => tabulate(n2)(f(i1, _)))

  /** Returns a three-dimensional array containing values of a given function
   *  over ranges of integer values starting from `0`.
   *
   *  @param   n1  the number of elements in the 1st dimension
   *  @param   n2  the number of elements in the 2nd dimension
   *  @param   n3  the number of elements in the 3rd dimension
   *  @param   f   The function computing element values
   */
  def tabulate[T: ClassTag](n1: Int, n2: Int, n3: Int)(f: (Int, Int, Int) => T): Array[Array[Array[T]]] =
    tabulate(n1)(i1 => tabulate(n2, n3)(f(i1, _, _)))

  /** Returns a four-dimensional array containing values of a given function
   *  over ranges of integer values starting from `0`.
   *
   *  @param   n1  the number of elements in the 1st dimension
   *  @param   n2  the number of elements in the 2nd dimension
   *  @param   n3  the number of elements in the 3rd dimension
   *  @param   n4  the number of elements in the 4th dimension
   *  @param   f   The function computing element values
   */
  def tabulate[T: ClassTag](n1: Int, n2: Int, n3: Int, n4: Int)(f: (Int, Int, Int, Int) => T): Array[Array[Array[Array[T]]]] =
    tabulate(n1)(i1 => tabulate(n2, n3, n4)(f(i1, _, _, _)))

  /** Returns a five-dimensional array containing values of a given function
   *  over ranges of integer values starting from `0`.
   *
   *  @param   n1  the number of elements in the 1st dimension
   *  @param   n2  the number of elements in the 2nd dimension
   *  @param   n3  the number of elements in the 3rd dimension
   *  @param   n4  the number of elements in the 4th dimension
   *  @param   n5  the number of elements in the 5th dimension
   *  @param   f   The function computing element values
   */
  def tabulate[T: ClassTag](n1: Int, n2: Int, n3: Int, n4: Int, n5: Int)(f: (Int, Int, Int, Int, Int) => T): Array[Array[Array[Array[Array[T]]]]] =
    tabulate(n1)(i1 => tabulate(n2, n3, n4, n5)(f(i1, _, _, _, _)))

  /** Returns an array containing a sequence of increasing integers in a range.
   *
   *  @param start  the start value of the array
   *  @param end    the end value of the array, exclusive (in other words, this is the first value '''not''' returned)
   *  @return  the array with values in range `start, start + 1, ..., end - 1`
   *  up to, but excluding, `end`.
   */
  def range(start: Int, end: Int): Array[Int] = range(start, end, 1)

  /** Returns an array containing equally spaced values in some integer interval.
   *
   *  @param start the start value of the array
   *  @param end   the end value of the array, exclusive (in other words, this is the first value '''not''' returned)
   *  @param step  the increment value of the array (may not be zero)
   *  @return      the array with values in `start, start + step, ...` up to, but excluding `end`
   */
  def range(start: Int, end: Int, step: Int): Array[Int] = {
    if (step == 0) throw new IllegalArgumentException("zero step")
    val b = newBuilder[Int]
    b.sizeHint(immutable.Range.count(start, end, step, isInclusive = false))

    var i = start
    while (if (step < 0) end < i else i < end) {
      b += i
      i += step
    }
    b.result()
  }

  /** Returns an array containing repeated applications of a function to a start value.
   *
   *  @param start the start value of the array
   *  @param len   the number of elements returned by the array
   *  @param f     the function that is repeatedly applied
   *  @return      the array returning `len` values in the sequence `start, f(start), f(f(start)), ...`
   */
  def iterate[T: ClassTag](start: T, len: Int)(f: T => T): Array[T] = {
    val b = newBuilder[T]

    if (len > 0) {
      b.sizeHint(len)
      var acc = start
      var i = 1
      b += acc

      while (i < len) {
        acc = f(acc)
        i += 1
        b += acc
      }
    }
    b.result()
  }

  /** Called in a pattern match like `{ case Array(x,y,z) => println('3 elements')}`.
   *
   *  @param x the selector value
   *  @return  sequence wrapped in a [[scala.Some]], if `x` is a Seq, otherwise `None`
   */
  def unapplySeq[T](x: Array[T]): Option[IndexedSeq[T]] =
    if (x == null) None else Some(x.toIndexedSeq)
    // !!! the null check should to be necessary, but without it 2241 fails. Seems to be a bug
    // in pattern matcher.  @PP: I noted in #4364 I think the behavior is correct.
}

/** Arrays are mutable, indexed collections of values. `Array[T]` is Scala's representation
 *  for Java's `T[]`.
 *
 *  {{{
 *  val numbers = Array(1, 2, 3, 4)
 *  val first = numbers(0) // read the first element
 *  numbers(3) = 100 // replace the 4th array element with 100
 *  val biggerNumbers = numbers.map(_ * 2) // multiply all numbers by two
 *  }}}
 *
 *  Arrays make use of two common pieces of Scala syntactic sugar, shown on lines 2 and 3 of the above
 *  example code.
 *  Line 2 is translated into a call to `apply(Int)`, while line 3 is translated into a call to
 *  `update(Int, T)`.
 *
 *  Two implicit conversions exist in [[scala.Predef]] that are frequently applied to arrays: a conversion
 *  to [[scala.collection.mutable.ArrayOps]] (shown on line 4 of the example above) and a conversion
 *  to [[scala.collection.mutable.WrappedArray]] (a subtype of [[scala.collection.Seq]]).
 *  Both types make available many of the standard operations found in the Scala collections API.
 *  The conversion to `ArrayOps` is temporary, as all operations defined on `ArrayOps` return an `Array`,
 *  while the conversion to `WrappedArray` is permanent as all operations return a `WrappedArray`.
 *
 *  The conversion to `ArrayOps` takes priority over the conversion to `WrappedArray`. For instance,
 *  consider the following code:
 *
 *  {{{
 *  val arr = Array(1, 2, 3)
 *  val arrReversed = arr.reverse
 *  val seqReversed : Seq[Int] = arr.reverse
 *  }}}
 *
 *  Value `arrReversed` will be of type `Array[Int]`, with an implicit conversion to `ArrayOps` occurring
 *  to perform the `reverse` operation. The value of `seqReversed`, on the other hand, will be computed
 *  by converting to `WrappedArray` first and invoking the variant of `reverse` that returns another
 *  `WrappedArray`.
 *
 *  @author Martin Odersky
 *  @version 1.0
 *  @see [[http://www.scala-lang.org/files/archive/spec/2.11/ Scala Language Specification]], for in-depth information on the transformations the Scala compiler makes on Arrays (Sections 6.6 and 6.15 respectively.)
 *  @see [[http://docs.scala-lang.org/sips/completed/scala-2-8-arrays.html "Scala 2.8 Arrays"]] the Scala Improvement Document detailing arrays since Scala 2.8.
 *  @see [[http://docs.scala-lang.org/overviews/collections/arrays.html "The Scala 2.8 Collections' API"]] section on `Array` by Martin Odersky for more information.
 *  @hideImplicitConversion scala.Predef.booleanArrayOps
 *  @hideImplicitConversion scala.Predef.byteArrayOps
 *  @hideImplicitConversion scala.Predef.charArrayOps
 *  @hideImplicitConversion scala.Predef.doubleArrayOps
 *  @hideImplicitConversion scala.Predef.floatArrayOps
 *  @hideImplicitConversion scala.Predef.intArrayOps
 *  @hideImplicitConversion scala.Predef.longArrayOps
 *  @hideImplicitConversion scala.Predef.refArrayOps
 *  @hideImplicitConversion scala.Predef.shortArrayOps
 *  @hideImplicitConversion scala.Predef.unitArrayOps
 *  @hideImplicitConversion scala.Predef._booleanArrayOps
 *  @hideImplicitConversion scala.Predef._byteArrayOps
 *  @hideImplicitConversion scala.Predef._charArrayOps
 *  @hideImplicitConversion scala.Predef._doubleArrayOps
 *  @hideImplicitConversion scala.Predef._floatArrayOps
 *  @hideImplicitConversion scala.Predef._intArrayOps
 *  @hideImplicitConversion scala.Predef._longArrayOps
 *  @hideImplicitConversion scala.Predef._refArrayOps
 *  @hideImplicitConversion scala.Predef._shortArrayOps
 *  @hideImplicitConversion scala.Predef._unitArrayOps
 *  @hideImplicitConversion scala.LowPriorityImplicits.wrapRefArray
 *  @hideImplicitConversion scala.LowPriorityImplicits.wrapIntArray
 *  @hideImplicitConversion scala.LowPriorityImplicits.wrapDoubleArray
 *  @hideImplicitConversion scala.LowPriorityImplicits.wrapLongArray
 *  @hideImplicitConversion scala.LowPriorityImplicits.wrapFloatArray
 *  @hideImplicitConversion scala.LowPriorityImplicits.wrapCharArray
 *  @hideImplicitConversion scala.LowPriorityImplicits.wrapByteArray
 *  @hideImplicitConversion scala.LowPriorityImplicits.wrapShortArray
 *  @hideImplicitConversion scala.LowPriorityImplicits.wrapBooleanArray
 *  @hideImplicitConversion scala.LowPriorityImplicits.wrapUnitArray
 *  @hideImplicitConversion scala.LowPriorityImplicits.genericWrapArray
 *  @define coll array
 *  @define Coll `Array`
 *  @define orderDependent
 *  @define orderDependentFold
 *  @define mayNotTerminateInf
 *  @define willNotTerminateInf
 *  @define collectExample
 *  @define undefinedorder
 *  @define thatinfo the class of the returned collection. In the standard library configuration,
 *    `That` is either `Array[B]` if an ClassTag is available for B or `ArraySeq[B]` otherwise.
 *  @define zipthatinfo $thatinfo
 *  @define bfinfo an implicit value of class `CanBuildFrom` which determines the result class `That` from the current
 *    representation type `Repr` and the new element type `B`.
 */
final class Array[T](_length: Int) extends java.io.Serializable with java.lang.Cloneable {

  /** The length of the array */
  def length: Int = throw new Error()

  /** The element at given index.
   *
   *  Indices start at `0`; `xs.apply(0)` is the first element of array `xs`.
   *  Note the indexing syntax `xs(i)` is a shorthand for `xs.apply(i)`.
   *
   *  @param    i   the index
   *  @return       the element at the given index
   *  @throws       ArrayIndexOutOfBoundsException if `i < 0` or `length <= i`
   */
  def apply(i: Int): T = throw new Error()

  /** Update the element at given index.
   *
   *  Indices start at `0`; `xs.update(i, x)` replaces the i^th^ element in the array.
   *  Note the syntax `xs(i) = x` is a shorthand for `xs.update(i, x)`.
   *
   *  @param    i   the index
   *  @param    x   the value to be written at index `i`
   *  @throws       ArrayIndexOutOfBoundsException if `i < 0` or `length <= i`
   */
  def update(i: Int, x: T) { throw new Error() }

  /** Clone the Array.
   *
   *  @return A clone of the Array.
   */
  override def clone(): Array[T] = throw new Error()
}