structArray<Element>
| Inheritance |
ArrayLiteralConvertible, CollectionType, CustomDebugStringConvertible, CustomStringConvertible, Indexable, MutableCollectionType, MutableIndexable, MutableSliceable, RangeReplaceableCollectionType, SequenceType, _ArrayType, _DestructorSafeContainer, _Reflectable
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| Associated Types |
Type alias inferred.
Type alias inferred.
Type alias inferred.
Type alias inferred. |
| Import |
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Initializers
Construct an empty Array.
Declaration
init()
Construct from an arbitrary sequence with elements of type Element.
Declaration
init<S:SequenceTypewhereS.Generator.Element==_Buffer.Element>(_s:S)
Declared In
Array
, RangeReplaceableCollectionType
Create an instance containing elements.
Declaration
init(arrayLiteralelements:Element...)
Construct a Array of count elements, each initialized to
repeatedValue.
Declaration
init(count:Int,repeatedValue:Element)
Instance Variables
The number of elements the Array can store without reallocation.
Declaration
varcapacity:Int{get}
A textual representation of self, suitable for debugging.
Declaration
vardebugDescription:String{get}
A "past-the-end" element index; the successor of the last valid subscript argument.
Declaration
varendIndex:Int{get}
Returns the first element of self, or nil if self is empty.
Complexity: O(1)
Declaration
varfirst:Element? {get}
Declared In
CollectionType
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
Declared In
CollectionType
Returns true iff self is empty.
Complexity: O(1)
Declaration
varisEmpty:Bool{get}
Declared In
CollectionType
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
varlazy:LazyCollection<Array<Element>>{get}
Declared In
CollectionType
Always zero, which is the index of the first element when non-empty.
Declaration
varstartIndex:Int{get}
5 inherited items hidden. (Show all)
Subscripts
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
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
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
mutatingfuncappend(newElement:Element)
Declared In
Array, RangeReplaceableCollectionType
Append the elements of newElements to self.
Complexity: O(length of result).
Declaration
mutatingfuncappendContentsOf<S:SequenceTypewhereS.Generator.Element==Element>(newElements:S)
Append the elements of newElements to self.
Complexity: O(length of result).
Declaration
mutatingfuncappendContentsOf<C:CollectionTypewhereC.Generator.Element==Element>(newElements:C)
Append the elements of newElements to self.
Complexity: O(length of result).
Declaration
mutatingfuncappendContentsOf<S:SequenceTypewhereS.Generator.Element==Generator.Element>(newElements:S)
Declared In
RangeReplaceableCollectionType
Returns a subsequence containing all but the first element.
Complexity: O(1)
Declaration
funcdropFirst() ->ArraySlice<Element>
Declared In
SequenceType
Returns a subsequence containing all but the first n elements.
Requires: n >= 0
Complexity: O(n)
Declaration
funcdropFirst(n:Int) ->ArraySlice<Element>
Declared In
CollectionType, SequenceType
Returns a subsequence containing all but the last element.
Requires: self is a finite sequence.
Complexity: O(self.count)
Declaration
funcdropLast() ->ArraySlice<Element>
Declared In
SequenceType
Returns a subsequence containing all but the last n elements.
Requires: n >= 0
Complexity: O(self.count)
Declaration
funcdropLast(n:Int) ->ArraySlice<Element>
Declared In
CollectionType, SequenceType
Returns true iff self and other contain equivalent elements, using
isEquivalent as the equivalence test.
Requires: isEquivalent is an
equivalence relation.
Declaration
funcelementsEqual<OtherSequence:SequenceTypewhereOtherSequence.Generator.Element==Generator.Element>(other:OtherSequence, @noescapeisEquivalent: (Element,Element)throws->Bool)rethrows->Bool
Declared In
SequenceType
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() {("\(n): '\(c)'")}0: 'S'1: 'w'2: 'i'3: 'f'4: 't'
Declaration
funcenumerate() ->EnumerateSequence<Array<Element>>
Declared In
SequenceType
Returns an Array containing the elements of self,
in order, that satisfy the predicate includeElement.
Declaration
funcfilter(@noescapeincludeElement: (Element)throws->Bool)rethrows->[Element]
Declared In
SequenceType
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
funcflatMap<T>(@noescapetransform: (Element)throws->T?)rethrows->[T]
Declared In
SequenceType
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
funcflatMap<S:SequenceType>(transform: (Element)throws->S)rethrows->[S.Generator.Element]
Declared In
SequenceType
Call body on each element in self in the same order as a
for-in loop.
sequence.forEach{// body code}
is similar to:
forelementinsequence{// 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
funcforEach(@noescapebody: (Element)throws->Void)rethrows
Declared In
SequenceType
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
Declared In
CollectionType
Insert newElement at index i.
Requires: i <= count.
Complexity: O(self.count).
Declaration
mutatingfuncinsert(newElement:Element,atIndexi:Int)
Declared In
Array, RangeReplaceableCollectionType
Insert newElements at index i.
Invalidates all indices with respect to self.
Complexity: O(self.count + newElements.count).
Declaration
mutatingfuncinsertContentsOf<C:CollectionTypewhereC.Generator.Element==Generator.Element>(newElements:C,ati:Int)
Declared In
RangeReplaceableCollectionType
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
funclexicographicalCompare<OtherSequence:SequenceTypewhereOtherSequence.Generator.Element==Generator.Element>(other:OtherSequence, @noescapeisOrderedBefore: (Element,Element)throws->Bool)rethrows->Bool
Declared In
SequenceType
Returns an Array containing the results of mapping transform
over self.
Complexity: O(N).
Declaration
funcmap<T>(@noescapetransform: (Element)throws->T)rethrows->[T]
Declared In
CollectionType, SequenceType
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
funcmaxElement(@noescapeisOrderedBefore: (Element,Element)throws->Bool)rethrows->Element?
Declared In
SequenceType
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
funcminElement(@noescapeisOrderedBefore: (Element,Element)throws->Bool)rethrows->Element?
Declared In
SequenceType
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
Declared In
MutableCollectionType
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
mutatingfuncpopLast() ->Element?
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
funcprefix(maxLength:Int) ->ArraySlice<Element>
Declared In
CollectionType, SequenceType
Returns prefixUpTo(position.successor())
Complexity: O(1)
Declaration
funcprefixThrough(position:Int) ->ArraySlice<Element>
Declared In
CollectionType
Returns self[startIndex..<end]
Complexity: O(1)
Declaration
funcprefixUpTo(end:Int) ->ArraySlice<Element>
Declared In
CollectionType
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
funcreduce<T>(initial:T, @noescapecombine: (T,Element)throws->T)rethrows->T
Declared In
SequenceType
Remove all elements.
Postcondition: capacity == 0 iff keepCapacity is false.
Complexity: O(self.count).
Declaration
mutatingfuncremoveAll(keepCapacitykeepCapacity:Bool=default)
Declared In
Array, RangeReplaceableCollectionType
Remove and return the element at index i.
Invalidates all indices with respect to self.
Complexity: O(self.count).
Declaration
mutatingfuncremoveAtIndex(index:Int) ->Element
Declared In
Array, RangeReplaceableCollectionType
Remove the element at startIndex and return it.
Complexity: O(self.count)
Requires: !self.isEmpty.
Declaration
mutatingfuncremoveFirst() ->Element
Declared In
RangeReplaceableCollectionType
Remove the first n elements.
Complexity: O(self.count)
Requires: n >= 0 && self.count >= n.
Declaration
mutatingfuncremoveFirst(n:Int)
Declared In
RangeReplaceableCollectionType
Remove an element from the end of the Array in O(1).
Requires: count > 0.
Declaration
mutatingfuncremoveLast() ->Element
Declared In
Array, RangeReplaceableCollectionType
Remove the last n elements.
Complexity: O(self.count)
Requires: n >= 0 && self.count >= n.
Declaration
mutatingfuncremoveLast(n:Int)
Declared In
RangeReplaceableCollectionType
Remove the indicated subRange of elements.
Invalidates all indices with respect to self.
Complexity: O(self.count).
Declaration
Declared In
RangeReplaceableCollectionType
Replace the given subRange of elements with newElements.
Complexity: O(subRange.count) if subRange.endIndex
== self.endIndex and newElements.isEmpty, O(N) otherwise.
Declaration
mutatingfuncreplaceRange<C:CollectionTypewhereC.Generator.Element==_Buffer.Element>(subRange:Range<Int>,withnewElements:C)
Reserve enough space to store minimumCapacity elements.
Postcondition: capacity >= minimumCapacity and the array has
mutable contiguous storage.
Complexity: O(self.count).
Declaration
mutatingfuncreserveCapacity(minimumCapacity:Int)
Declared In
Array, RangeReplaceableCollectionType
Returns the elements of self in reverse order.
Complexity: O(1)
Declaration
funcreverse() ->ReverseCollection<Array<Element>>
Declared In
CollectionType, SequenceType
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
funcsort(@noescapeisOrderedBefore: (Element,Element) ->Bool) ->[Element]
Declared In
MutableCollectionType, SequenceType
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
mutatingfuncsortInPlace(@noescapeisOrderedBefore: (Element,Element) ->Bool)
Declared In
MutableCollectionType
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
funcsplit(maxSplit:Int=default,allowEmptySlices:Bool=default, @noescapeisSeparator: (Element)throws->Bool)rethrows->[ArraySlice<Element>]
Declared In
CollectionType, SequenceType
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
funcstartsWith<OtherSequence:SequenceTypewhereOtherSequence.Generator.Element==Generator.Element>(other:OtherSequence, @noescapeisEquivalent: (Element,Element)throws->Bool)rethrows->Bool
Declared In
SequenceType
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
funcsuffix(maxLength:Int) ->ArraySlice<Element>
Declared In
CollectionType, SequenceType
Returns self[start..<endIndex]
Complexity: O(1)
Declaration
funcsuffixFrom(start:Int) ->ArraySlice<Element>
Declared In
CollectionType
Returns a value less than or equal to the number of elements in
self, nondestructively.
Complexity: O(N).
Declaration
funcunderestimateCount() ->Int
Declared In
CollectionType, SequenceType
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
funcwithUnsafeBufferPointer<R>(@noescapebody: (UnsafeBufferPointer<Element>)throws->R)rethrows->R
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
mutatingfuncwithUnsafeMutableBufferPointer<R>(@noescapebody: (inoutUnsafeMutableBufferPointer<Element>)throws->R)rethrows->R
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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
A concatenation of the elements of self.
Declaration
funcflatten() ->FlattenCollection<Array<Element>>
Declared In
CollectionType
1 inherited item hidden. (Show all)
Where Generator.Element : CollectionType, Index : BidirectionalIndexType, Generator.Element.Index : BidirectionalIndexType
A concatenation of the elements of self.
Declaration
funcflatten() ->FlattenBidirectionalCollection<Array<Element>>
Declared In
CollectionType
1 inherited item hidden. (Show all)
Where Generator.Element : Comparable
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
funclexicographicalCompare<OtherSequence:SequenceTypewhereOtherSequence.Generator.Element==Generator.Element>(other:OtherSequence) ->Bool
Declared In
SequenceType
Returns the maximum element in self or nil if the sequence is empty.
Complexity: O(elements.count).
Declaration
funcmaxElement() ->Element?
Declared In
SequenceType
Returns the minimum element in self or nil if the sequence is empty.
Complexity: O(elements.count).
Declaration
funcminElement() ->Element?
Declared In
SequenceType
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
funcsort() ->[Element]
Declared In
MutableCollectionType, SequenceType
4 inherited items hidden. (Show all)
Where Generator.Element : Equatable
Returns true iff element is in self.
Declaration
funccontains(element:Element) ->Bool
Declared In
SequenceType
Returns true iff self and other contain the same elements in the
same order.
Declaration
funcelementsEqual<OtherSequence:SequenceTypewhereOtherSequence.Generator.Element==Generator.Element>(other:OtherSequence) ->Bool
Declared In
SequenceType
Returns the first index where value appears in self or nil if
value is not found.
Complexity: O(self.count).
Declaration
funcindexOf(element:Element) ->Int?
Declared In
CollectionType
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
funcsplit(separator:Element,maxSplit:Int=default,allowEmptySlices:Bool=default) ->[ArraySlice<Element>]
Declared In
CollectionType, SequenceType
Returns true iff the initial elements of self are equal to prefix.
Returns true if other is empty.
Declaration
funcstartsWith<OtherSequence:SequenceTypewhereOtherSequence.Generator.Element==Generator.Element>(other:OtherSequence) ->Bool
Declared In
SequenceType
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Where Generator.Element : SequenceType
A concatenation of the elements of self.
Declaration
funcflatten() ->FlattenSequence<Array<Element>>
Declared In
SequenceType
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
funcjoinWithSeparator<Separator:SequenceTypewhereSeparator.Generator.Element==Generator.Element.Generator.Element>(separator:Separator) ->JoinSequence<Array<Element>>
Declared In
SequenceType
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Where Generator.Element == String
Interpose the separator between elements of self, then concatenate
the result. For example:
["foo","bar","baz"].joinWithSeparator("-|-")// "foo-|-bar-|-baz"
Declaration
Declared In
SequenceType
1 inherited item hidden. (Show all)
Where Index : RandomAccessIndexType, Generator.Element : Comparable
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
Declared In
MutableCollectionType
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
mutatingfuncsortInPlace()
Declared In
MutableCollectionType
2 inherited items hidden. (Show all)
Arrayis 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>, andArraySlice<Element>. When you read the word "array" here in a normal typeface, it applies to all three of them.Value Semantics
Each array variable,
letbinding, 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:(Of course, if the array stores
classreferences, 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, whereNis 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, andArraySliceshare an exponential growth strategy that makesappenda constant time operation when amortized over many invocations. In addition to acountproperty, these array types have acapacitythat reflects their potential to store elements without reallocation, and when you know how many elements you'll store, you can callreserveCapacityto preemptively reallocate and prevent intermediate reallocations.Objective-C Bridge
The main distinction between
Arrayand the other array types is that it interoperates seamlessly and efficiently with Objective-C.Array<Element>is considered bridged to Objective-C iffElementis bridged to Objective-C.When
Elementis aclassor@objcprotocol type,Arraymay store its elements in anNSArray. Since any arbitrary subclass ofNSArraycan become anArray, there are no guarantees about representation or efficiency in this case (see alsoContiguousArray). SinceNSArrayis 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 costO(N)time and space, whereNis the length of the array (or more, if the underlyingNSArrayhas unusual performance characteristics).Bridging to Objective-C
Any bridged
Arraycan be implicitly converted to anNSArray. WhenElementis aclassor@objcprotocol, bridging takes O(1) time and O(1) space. OtherArrays 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
NSArraycan be implicitly or explicitly converted to any bridgedArray<Element>. This conversion callscopyWithZoneon theNSArray, to ensure it won't be modified, and stores the result in theArray. Type-checking, to ensure theNSArray's elements match or can be bridged toElement, is deferred until the first element access.