Array

struct Array<Element>

Array is an efficient, tail-growable random-access collection of arbitrary elements.

Common Properties of Array Types

The information in this section applies to all three of Swift's array types, Array<Element>, ContiguousArray<Element>, and ArraySlice<Element>. When you read the word "array" here in a normal typeface, it applies to all three of them.

Value Semantics

Each array variable, let binding, or stored property has an independent value that includes the values of all of its elements. Therefore, mutations to the array are not observable through its copies:

var a = [1, 2, 3]
var b = a
b[0] = 4
print("a=\(a), b=\(b)")     // a=[1, 2, 3], b=[4, 2, 3]

(Of course, if the array stores class references, the objects are shared; only the values of the references are independent.)

Arrays use Copy-on-Write so that their storage and elements are only copied lazily, upon mutation, when more than one array instance is using the same buffer. Therefore, the first in any sequence of mutating operations may cost O(N) time and space, where N is the length of the array.

Growth and Capacity

When an array's contiguous storage fills up, new storage must be allocated and elements must be moved to the new storage. Array, ContiguousArray, and ArraySlice share an exponential growth strategy that makes append a constant time operation when amortized over many invocations. In addition to a count property, these array types have a capacity that reflects their potential to store elements without reallocation, and when you know how many elements you'll store, you can call reserveCapacity to preemptively reallocate and prevent intermediate reallocations.

Objective-C Bridge

The main distinction between Array and the other array types is that it interoperates seamlessly and efficiently with Objective-C.

Array<Element> is considered bridged to Objective-C iff Element is bridged to Objective-C.

When Element is a class or @objc protocol type, Array may store its elements in an NSArray. Since any arbitrary subclass of NSArray can become an Array, there are no guarantees about representation or efficiency in this case (see also ContiguousArray). Since NSArray is immutable, it is just as though the storage was shared by some copy: the first in any sequence of mutating operations causes elements to be copied into unique, contiguous storage which may cost O(N) time and space, where N is the length of the array (or more, if the underlying NSArray has unusual performance characteristics).

Bridging to Objective-C

Any bridged Array can be implicitly converted to an NSArray. When Element is a class or @objc protocol, bridging takes O(1) time and O(1) space. Other Arrays must be bridged element-by-element, allocating a new object for each element, at a cost of at least O(count) time and space.

Bridging from Objective-C

An NSArray can be implicitly or explicitly converted to any bridged Array<Element>. This conversion calls copyWithZone on the NSArray, to ensure it won't be modified, and stores the result in the Array. Type-checking, to ensure the NSArray's elements match or can be bridged to Element, is deferred until the first element access.

Inheritance ArrayLiteralConvertible, CollectionType, CustomDebugStringConvertible, CustomStringConvertible, Indexable, MutableCollectionType, MutableIndexable, MutableSliceable, RangeReplaceableCollectionType, SequenceType, _ArrayType, _DestructorSafeContainer, _Reflectable View Protocol Hierarchy →
Associated Types
Generator = IndexingGenerator<Array<Element>>

Type alias inferred.

Element = Element

Type alias inferred.

Index = Int

Type alias inferred.

SubSequence = ArraySlice<Element>

Type alias inferred.
Import import Swift

Initializers

init()

Construct an empty Array.

Declaration

init()
init(_:)

Construct from an arbitrary sequence with elements of type Element.

Declaration

init<S : SequenceType where S.Generator.Element == _Buffer.Element>(_ s: S)

Declared In

Array , RangeReplaceableCollectionType
init(arrayLiteral:)

Create an instance containing elements.

Declaration

init(arrayLiteral elements: Element...)
init(count:repeatedValue:)

Construct a Array of count elements, each initialized to repeatedValue.

Declaration

init(count: Int, repeatedValue: Element)

Instance Variables

var capacity: Int

The number of elements the Array can store without reallocation.

Declaration

var capacity: Int { get }
var count: Int

The number of elements the Array stores.

Declaration

var count: Int { get }
var debugDescription: String

A textual representation of self, suitable for debugging.

Declaration

var debugDescription: String { get }
var description: String

A textual representation of self.

Declaration

var description: String { get }
var endIndex: Int

A "past-the-end" element index; the successor of the last valid subscript argument.

Declaration

var endIndex: Int { get }
var first: Element?

Returns the first element of self, or nil if self is empty.

Complexity: O(1)

Declaration

var first: Element? { get }

Declared In

CollectionType
var indices: Range<Int>

Returns the range of valid index values.

The result's endIndex is the same as that of self. Because Range is half-open, iterating the values of the result produces all valid subscript arguments for self, omitting its endIndex.

Declaration

var indices: Range<Int> { get }

Declared In

CollectionType
var isEmpty: Bool

Returns true iff self is empty.

Complexity: O(1)

Declaration

var isEmpty: Bool { get }

Declared In

CollectionType
var last: Element?

Declaration

var last: Element? { get }

Declared In

CollectionType
var lazy: LazyCollection<Array<Element>>

A collection with contents identical to self, but on which normally-eager operations such as map and filter are implemented lazily.

See Also: LazySequenceType, LazyCollectionType.

Declaration

var lazy: LazyCollection<Array<Element>> { get }

Declared In

CollectionType
var startIndex: Int

Always zero, which is the index of the first element when non-empty.

Declaration

var startIndex: Int { get }

Subscripts

subscript(_: Int)

Access the indexth element. Reading is O(1). Writing is O(1) unless self's storage is shared with another live array; O(count) if self does not wrap a bridged NSArray; otherwise the efficiency is unspecified..

Declaration

subscript(index: Int) -> Element
subscript(_: Range<Int>)

Access the elements indicated by the given half-open subRange.

Complexity: O(1).

Declaration

subscript(subRange: Range<Int>) -> ArraySlice<Element>

Declared In

Array, MutableCollectionType

Instance Methods

mutating func append(_:)

Append newElement to the Array.

Complexity: Amortized O(1) unless self's storage is shared with another live array; O(count) if self does not wrap a bridged NSArray; otherwise the efficiency is unspecified..

Declaration

mutating func append(newElement: Element)

Declared In

Array, RangeReplaceableCollectionType
mutating func appendContentsOf<S : SequenceType where S.Generator.Element == Element>(_: S)

Append the elements of newElements to self.

Complexity: O(length of result).

Declaration

mutating func appendContentsOf<S : SequenceType where S.Generator.Element == Element>(newElements: S)
mutating func appendContentsOf<C : CollectionType where C.Generator.Element == Element>(_: C)

Append the elements of newElements to self.

Complexity: O(length of result).

Declaration

mutating func appendContentsOf<C : CollectionType where C.Generator.Element == Element>(newElements: C)
mutating func appendContentsOf(_:)

Append the elements of newElements to self.

Complexity: O(length of result).

Declaration

mutating func appendContentsOf<S : SequenceType where S.Generator.Element == Generator.Element>(newElements: S)

Declared In

RangeReplaceableCollectionType
func contains(_:)

Returns true iff an element in self satisfies predicate.

Declaration

func contains(@noescape predicate: (Element) throws -> Bool) rethrows -> Bool

Declared In

SequenceType
func dropFirst()

Returns a subsequence containing all but the first element.

Complexity: O(1)

Declaration

func dropFirst() -> ArraySlice<Element>

Declared In

SequenceType
func dropFirst(_:)

Returns a subsequence containing all but the first n elements.

Requires: n >= 0 Complexity: O(n)

Declaration

func dropFirst(n: Int) -> ArraySlice<Element>

Declared In

CollectionType, SequenceType
func dropLast()

Returns a subsequence containing all but the last element.

Requires: self is a finite sequence. Complexity: O(self.count)

Declaration

func dropLast() -> ArraySlice<Element>

Declared In

SequenceType
func dropLast(_:)

Returns a subsequence containing all but the last n elements.

Requires: n >= 0 Complexity: O(self.count)

Declaration

func dropLast(n: Int) -> ArraySlice<Element>

Declared In

CollectionType, SequenceType
func elementsEqual(_:isEquivalent:)

Returns true iff self and other contain equivalent elements, using isEquivalent as the equivalence test.

Requires: isEquivalent is an equivalence relation.

Declaration

func elementsEqual<OtherSequence : SequenceType where OtherSequence.Generator.Element == Generator.Element>(other: OtherSequence, @noescape isEquivalent: (Element, Element) throws -> Bool) rethrows -> Bool

Declared In

SequenceType
func enumerate()

Returns a lazy SequenceType containing pairs (n, x), where ns are consecutive Ints starting at zero, and xs are the elements of base:

> for (n, c) in "Swift".characters.enumerate() {
    print("\(n): '\(c)'")
  }
0: 'S'
1: 'w'
2: 'i'
3: 'f'
4: 't'

Declaration

func enumerate() -> EnumerateSequence<Array<Element>>

Declared In

SequenceType
func filter(_:)

Returns an Array containing the elements of self, in order, that satisfy the predicate includeElement.

Declaration

func filter(@noescape includeElement: (Element) throws -> Bool) rethrows -> [Element]

Declared In

SequenceType
func flatMap<T>(_: (Element) throws -> T?)

Returns an Array containing the non-nil results of mapping transform over self.

Complexity: O(M + N), where M is the length of self and N is the length of the result.

Declaration

func flatMap<T>(@noescape transform: (Element) throws -> T?) rethrows -> [T]

Declared In

SequenceType
func flatMap<S : SequenceType>(_: (Element) throws -> S)

Returns an Array containing the concatenated results of mapping transform over self.

s.flatMap(transform)

is equivalent to

Array(s.map(transform).flatten())

Complexity: O(M + N), where M is the length of self and N is the length of the result.

Declaration

func flatMap<S : SequenceType>(transform: (Element) throws -> S) rethrows -> [S.Generator.Element]

Declared In

SequenceType
func forEach(_:)

Call body on each element in self in the same order as a for-in loop.

sequence.forEach {
  // body code
}

is similar to:

for element in sequence {
  // body code
}

Note: You cannot use the break or continue statement to exit the current call of the body closure or skip subsequent calls. Note: Using the return statement in the body closure will only exit from the current call to body, not any outer scope, and won't skip subsequent calls.

Complexity: O(self.count)

Declaration

func forEach(@noescape body: (Element) throws -> Void) rethrows

Declared In

SequenceType
func generate()

Declaration

func generate() -> IndexingGenerator<Array<Element>>

Declared In

CollectionType
func indexOf(_:)

Returns the first index where predicate returns true for the corresponding value, or nil if such value is not found.

Complexity: O(self.count).

Declaration

func indexOf(@noescape predicate: (Element) throws -> Bool) rethrows -> Int?

Declared In

CollectionType
mutating func insert(_:atIndex:)

Insert newElement at index i.

Requires: i <= count.

Complexity: O(self.count).

Declaration

mutating func insert(newElement: Element, atIndex i: Int)

Declared In

Array, RangeReplaceableCollectionType
mutating func insertContentsOf(_:at:)

Insert newElements at index i.

Invalidates all indices with respect to self.

Complexity: O(self.count + newElements.count).

Declaration

mutating func insertContentsOf<C : CollectionType where C.Generator.Element == Generator.Element>(newElements: C, at i: Int)

Declared In

RangeReplaceableCollectionType
func lexicographicalCompare(_:isOrderedBefore:)

Returns true iff self precedes other in a lexicographical ("dictionary") ordering, using isOrderedBefore as the comparison between elements.

Note: This method implements the mathematical notion of lexicographical ordering, which has no connection to Unicode. If you are sorting strings to present to the end-user, you should use String APIs that perform localized comparison.

Requires: isOrderedBefore is a strict weak ordering over the elements of self and other.

Declaration

func lexicographicalCompare<OtherSequence : SequenceType where OtherSequence.Generator.Element == Generator.Element>(other: OtherSequence, @noescape isOrderedBefore: (Element, Element) throws -> Bool) rethrows -> Bool

Declared In

SequenceType
func map(_:)

Returns an Array containing the results of mapping transform over self.

Complexity: O(N).

Declaration

func map<T>(@noescape transform: (Element) throws -> T) rethrows -> [T]

Declared In

CollectionType, SequenceType
func maxElement(_:)

Returns the maximum element in self or nil if the sequence is empty.

Complexity: O(elements.count).

Requires: isOrderedBefore is a strict weak ordering over self.

Declaration

func maxElement(@noescape isOrderedBefore: (Element, Element) throws -> Bool) rethrows -> Element?

Declared In

SequenceType
func minElement(_:)

Returns the minimum element in self or nil if the sequence is empty.

Complexity: O(elements.count).

Requires: isOrderedBefore is a strict weak ordering over self.

Declaration

func minElement(@noescape isOrderedBefore: (Element, Element) throws -> Bool) rethrows -> Element?

Declared In

SequenceType
mutating func partition(_:isOrderedBefore:)

Re-order the given range of elements in self and return a pivot index p.

Postcondition: For all i in range.startIndex..<p, and j in p..<range.endIndex, less(self[i], self[j]) && !less(self[j], self[p]). Only returns range.endIndex when self is empty.

Requires: isOrderedBefore is a strict weak ordering over the elements in self.

Declaration

mutating func partition(range: Range<Int>, isOrderedBefore: (Element, Element) -> Bool) -> Int

Declared In

MutableCollectionType
mutating func popLast()

If !self.isEmpty, remove the last element and return it, otherwise return nil.

Complexity: O(self.count) if the array is bridged, otherwise O(1).

Declaration

mutating func popLast() -> Element?
func prefix(_:)

Returns a subsequence, up to maxLength in length, containing the initial elements.

If maxLength exceeds self.count, the result contains all the elements of self.

Requires: maxLength >= 0 Complexity: O(maxLength)

Declaration

func prefix(maxLength: Int) -> ArraySlice<Element>

Declared In

CollectionType, SequenceType
func prefixThrough(_:)

Returns prefixUpTo(position.successor())

Complexity: O(1)

Declaration

func prefixThrough(position: Int) -> ArraySlice<Element>

Declared In

CollectionType
func prefixUpTo(_:)

Returns self[startIndex..<end]

Complexity: O(1)

Declaration

func prefixUpTo(end: Int) -> ArraySlice<Element>

Declared In

CollectionType
func reduce(_:combine:)

Returns the result of repeatedly calling combine with an accumulated value initialized to initial and each element of self, in turn, i.e. return combine(combine(...combine(combine(initial, self[0]), self[1]),...self[count-2]), self[count-1]).

Declaration

func reduce<T>(initial: T, @noescape combine: (T, Element) throws -> T) rethrows -> T

Declared In

SequenceType
mutating func removeAll(keepCapacity:)

Remove all elements.

Postcondition: capacity == 0 iff keepCapacity is false.

Complexity: O(self.count).

Declaration

mutating func removeAll(keepCapacity keepCapacity: Bool = default)

Declared In

Array, RangeReplaceableCollectionType
mutating func removeAtIndex(_:)

Remove and return the element at index i.

Invalidates all indices with respect to self.

Complexity: O(self.count).

Declaration

mutating func removeAtIndex(index: Int) -> Element

Declared In

Array, RangeReplaceableCollectionType
mutating func removeFirst()

Remove the element at startIndex and return it.

Complexity: O(self.count) Requires: !self.isEmpty.

Declaration

mutating func removeFirst() -> Element

Declared In

RangeReplaceableCollectionType
mutating func removeFirst(_:)

Remove the first n elements.

Complexity: O(self.count) Requires: n >= 0 && self.count >= n.

Declaration

mutating func removeFirst(n: Int)

Declared In

RangeReplaceableCollectionType
mutating func removeLast()

Remove an element from the end of the Array in O(1).

Requires: count > 0.

Declaration

mutating func removeLast() -> Element

Declared In

Array, RangeReplaceableCollectionType
mutating func removeLast(_:)

Remove the last n elements.

Complexity: O(self.count) Requires: n >= 0 && self.count >= n.

Declaration

mutating func removeLast(n: Int)

Declared In

RangeReplaceableCollectionType
mutating func removeRange(_:)

Remove the indicated subRange of elements.

Invalidates all indices with respect to self.

Complexity: O(self.count).

Declaration

mutating func removeRange(subRange: Range<Int>)

Declared In

RangeReplaceableCollectionType
mutating func replaceRange(_:with:)

Replace the given subRange of elements with newElements.

Complexity: O(subRange.count) if subRange.endIndex == self.endIndex and newElements.isEmpty, O(N) otherwise.

Declaration

mutating func replaceRange<C : CollectionType where C.Generator.Element == _Buffer.Element>(subRange: Range<Int>, with newElements: C)
mutating func reserveCapacity(_:)

Reserve enough space to store minimumCapacity elements.

Postcondition: capacity >= minimumCapacity and the array has mutable contiguous storage.

Complexity: O(self.count).

Declaration

mutating func reserveCapacity(minimumCapacity: Int)

Declared In

Array, RangeReplaceableCollectionType
func reverse()

Returns the elements of self in reverse order.

Complexity: O(1)

Declaration

func reverse() -> ReverseCollection<Array<Element>>

Declared In

CollectionType, SequenceType
func sort(_:)

Returns an Array containing the sorted elements of source according to isOrderedBefore.

The sorting algorithm is not stable (can change the relative order of elements for which isOrderedBefore does not establish an order).

Requires: isOrderedBefore is a strict weak ordering over the elements in self.

Declaration

func sort(@noescape isOrderedBefore: (Element, Element) -> Bool) -> [Element]

Declared In

MutableCollectionType, SequenceType
mutating func sortInPlace(_:)

Sort self in-place according to isOrderedBefore.

The sorting algorithm is not stable (can change the relative order of elements for which isOrderedBefore does not establish an order).

Requires: isOrderedBefore is a strict weak ordering over the elements in self.

Declaration

mutating func sortInPlace(@noescape isOrderedBefore: (Element, Element) -> Bool)

Declared In

MutableCollectionType
func split(_:allowEmptySlices:isSeparator:)

Returns the maximal SubSequences of self, in order, that don't contain elements satisfying the predicate isSeparator.

maxSplit: The maximum number of SubSequences to return, minus 1. If maxSplit + 1 SubSequences are returned, the last one is a suffix of self containing the remaining elements. The default value is Int.max.

allowEmptySubsequences: If true, an empty SubSequence is produced in the result for each pair of consecutive elements satisfying isSeparator. The default value is false.

Requires: maxSplit >= 0

Declaration

func split(maxSplit: Int = default, allowEmptySlices: Bool = default, @noescape isSeparator: (Element) throws -> Bool) rethrows -> [ArraySlice<Element>]

Declared In

CollectionType, SequenceType
func startsWith(_:isEquivalent:)

Returns true iff self begins with elements equivalent to those of other, using isEquivalent as the equivalence test. Returns true if other is empty.

Requires: isEquivalent is an equivalence relation.

Declaration

func startsWith<OtherSequence : SequenceType where OtherSequence.Generator.Element == Generator.Element>(other: OtherSequence, @noescape isEquivalent: (Element, Element) throws -> Bool) rethrows -> Bool

Declared In

SequenceType
func suffix(_:)

Returns a slice, up to maxLength in length, containing the final elements of s.

If maxLength exceeds s.count, the result contains all the elements of s.

Requires: maxLength >= 0 Complexity: O(self.count)

Declaration

func suffix(maxLength: Int) -> ArraySlice<Element>

Declared In

CollectionType, SequenceType
func suffixFrom(_:)

Returns self[start..<endIndex]

Complexity: O(1)

Declaration

func suffixFrom(start: Int) -> ArraySlice<Element>

Declared In

CollectionType
func underestimateCount()

Returns a value less than or equal to the number of elements in self, nondestructively.

Complexity: O(N).

Declaration

func underestimateCount() -> Int

Declared In

CollectionType, SequenceType
func withUnsafeBufferPointer(_:)

Call body(p), where p is a pointer to the Array's contiguous storage. If no such storage exists, it is first created.

Often, the optimizer can eliminate bounds checks within an array algorithm, but when that fails, invoking the same algorithm on body's argument lets you trade safety for speed.

Declaration

func withUnsafeBufferPointer<R>(@noescape body: (UnsafeBufferPointer<Element>) throws -> R) rethrows -> R
mutating func withUnsafeMutableBufferPointer(_:)

Call body(p), where p is a pointer to the Array's mutable contiguous storage. If no such storage exists, it is first created.

Often, the optimizer can eliminate bounds- and uniqueness-checks within an array algorithm, but when that fails, invoking the same algorithm on body's argument lets you trade safety for speed.

Warning: Do not rely on anything about self (the Array that is the target of this method) during the execution of body: it may not appear to have its correct value. Instead, use only the UnsafeMutableBufferPointer argument to body.

Declaration

mutating func withUnsafeMutableBufferPointer<R>(@noescape body: (inout UnsafeMutableBufferPointer<Element>) throws -> R) rethrows -> R

Conditionally Inherited Items

The initializers, methods, and properties listed below may be available on this type under certain conditions (such as methods that are available on Array when its elements are Equatable) or may not ever be available if that determination is beyond SwiftDoc.org's capabilities. Please open an issue on GitHub if you see something out of place!

Where Generator.Element : CollectionType

func flatten()

A concatenation of the elements of self.

Declaration

func flatten() -> FlattenCollection<Array<Element>>

Declared In

CollectionType

Where Generator.Element : CollectionType, Index : BidirectionalIndexType, Generator.Element.Index : BidirectionalIndexType

func flatten()

A concatenation of the elements of self.

Declaration

func flatten() -> FlattenBidirectionalCollection<Array<Element>>

Declared In

CollectionType

Where Generator.Element : Comparable

func lexicographicalCompare(_:)

Returns true iff self precedes other in a lexicographical ("dictionary") ordering, using "<" as the comparison between elements.

Note: This method implements the mathematical notion of lexicographical ordering, which has no connection to Unicode. If you are sorting strings to present to the end-user, you should use String APIs that perform localized comparison.

Declaration

func lexicographicalCompare<OtherSequence : SequenceType where OtherSequence.Generator.Element == Generator.Element>(other: OtherSequence) -> Bool

Declared In

SequenceType
func maxElement()

Returns the maximum element in self or nil if the sequence is empty.

Complexity: O(elements.count).

Declaration

func maxElement() -> Element?

Declared In

SequenceType
func minElement()

Returns the minimum element in self or nil if the sequence is empty.

Complexity: O(elements.count).

Declaration

func minElement() -> Element?

Declared In

SequenceType
func sort()

Returns an Array containing the sorted elements of source.

The sorting algorithm is not stable (can change the relative order of elements that compare equal).

Requires: The less-than operator (func <) defined in the Comparable conformance is a strict weak ordering over the elements in self.

Declaration

func sort() -> [Element]

Declared In

MutableCollectionType, SequenceType

Where Generator.Element : Equatable

func contains(_:)

Returns true iff element is in self.

Declaration

func contains(element: Element) -> Bool

Declared In

SequenceType
func elementsEqual(_:)

Returns true iff self and other contain the same elements in the same order.

Declaration

func elementsEqual<OtherSequence : SequenceType where OtherSequence.Generator.Element == Generator.Element>(other: OtherSequence) -> Bool

Declared In

SequenceType
func indexOf(_:)

Returns the first index where value appears in self or nil if value is not found.

Complexity: O(self.count).

Declaration

func indexOf(element: Element) -> Int?

Declared In

CollectionType
func split(_:maxSplit:allowEmptySlices:)

Returns the maximal SubSequences of self, in order, around a separator element.

maxSplit: The maximum number of SubSequences to return, minus 1. If maxSplit + 1 SubSequences are returned, the last one is a suffix of self containing the remaining elements. The default value is Int.max.

allowEmptySubsequences: If true, an empty SubSequence is produced in the result for each pair of consecutive elements satisfying isSeparator. The default value is false.

Requires: maxSplit >= 0

Declaration

func split(separator: Element, maxSplit: Int = default, allowEmptySlices: Bool = default) -> [ArraySlice<Element>]

Declared In

CollectionType, SequenceType
func startsWith(_:)

Returns true iff the initial elements of self are equal to prefix. Returns true if other is empty.

Declaration

func startsWith<OtherSequence : SequenceType where OtherSequence.Generator.Element == Generator.Element>(other: OtherSequence) -> Bool

Declared In

SequenceType

Where Generator.Element : SequenceType

func flatten()

A concatenation of the elements of self.

Declaration

func flatten() -> FlattenSequence<Array<Element>>

Declared In

SequenceType
func joinWithSeparator(_:)

Returns a view, whose elements are the result of interposing a given separator between the elements of the sequence self.

For example, [[1, 2, 3], [4, 5, 6], [7, 8, 9]].joinWithSeparator([-1, -2]) yields [1, 2, 3, -1, -2, 4, 5, 6, -1, -2, 7, 8, 9].

Declaration

func joinWithSeparator<Separator : SequenceType where Separator.Generator.Element == Generator.Element.Generator.Element>(separator: Separator) -> JoinSequence<Array<Element>>

Declared In

SequenceType

Where Generator.Element == String

func joinWithSeparator(_:)

Interpose the separator between elements of self, then concatenate the result. For example:

["foo", "bar", "baz"].joinWithSeparator("-|-") // "foo-|-bar-|-baz"

Declaration

func joinWithSeparator(separator: String) -> String

Declared In

SequenceType

Where Index : RandomAccessIndexType, Generator.Element : Comparable

mutating func partition(_:)

Re-order the given range of elements in self and return a pivot index p.

Postcondition: For all i in range.startIndex..<p, and j in p..<range.endIndex, less(self[i], self[j]) && !less(self[j], self[p]). Only returns range.endIndex when self is empty.

Requires: The less-than operator (func <) defined in the Comparable conformance is a strict weak ordering over the elements in self.

Declaration

mutating func partition(range: Range<Int>) -> Int

Declared In

MutableCollectionType
mutating func sortInPlace()

Sort self in-place.

The sorting algorithm is not stable (can change the relative order of elements that compare equal).

Requires: The less-than operator (func <) defined in the Comparable conformance is a strict weak ordering over the elements in self.

Declaration

mutating func sortInPlace()

Declared In

MutableCollectionType