struct Dictionary<Key : Hashable, Value> A hash-based mapping from Key to Value instances. Also a collection of key-value pairs with no defined ordering. Inheritance CollectionType, CustomDebugStringConvertible, CustomStringConvertible, DictionaryLiteralConvertible, Indexable, SequenceType, _ObjectiveCBridgeable, _Reflectable View Protocol Hierarchy → Associated Types Element = (Key, Value) Index = DictionaryIndex<Key, Value> Generator = DictionaryGenerator<Key, Value> Type alias inferred. SubSequence = Slice<Dictionary<Key, Value>> Type alias inferred. Import import Swift Initializers init() Create an empty dictionary. Declaration init() init(dictionaryLiteral:) Create an instance initialized with elements. Declaration init(dictionaryLiteral elements: (Key, Value)...) init(minimumCapacity:) Create a dictionary with at least the given number of elements worth of storage. The actual capacity will be the smallest power of 2 that's >= minimumCapacity. Declaration init(minimumCapacity: Int) Instance Variables var count: Int The number of entries in the dictionary. Complexity: O(1). 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: DictionaryIndex<Key, Value> The collection's "past the end" position. endIndex is not a valid argument to subscript, and is always reachable from startIndex by zero or more applications of successor(). Complexity: Amortized O(1) if self does not wrap a bridged NSDictionary, O(N) otherwise. Declaration var endIndex: DictionaryIndex<Key, Value> { get } var first: (Key, Value)? Returns the first element of self, or nil if self is empty. Complexity: O(1) Declaration var first: (Key, Value)? { get } Declared In CollectionType var indices: Range<DictionaryIndex<Key, Value>> 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<DictionaryIndex<Key, Value>> { get } Declared In CollectionType var isEmpty: Bool true iff count == 0. Declaration var isEmpty: Bool { get } Declared In Dictionary , CollectionType var keys: LazyMapCollection<[Key : Value], Key> A collection containing just the keys of self. Keys appear in the same order as they occur as the .0 member of key-value pairs in self. Each key in the result has a unique value. Declaration var keys: LazyMapCollection<[Key : Value], Key> { get } var lazy: LazyCollection<Dictionary<Key, Value>> 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<Dictionary<Key, Value>> { get } Declared In CollectionType var startIndex: DictionaryIndex<Key, Value> The position of the first element in a non-empty dictionary. Identical to endIndex in an empty dictionary. Complexity: Amortized O(1) if self does not wrap a bridged NSDictionary, O(N) otherwise. Declaration var startIndex: DictionaryIndex<Key, Value> { get } var values: LazyMapCollection<[Key : Value], Value> A collection containing just the values of self. Values appear in the same order as they occur as the .1 member of key-value pairs in self. Declaration var values: LazyMapCollection<[Key : Value], Value> { get } Subscripts subscript(_: DictionaryIndex<Key, Value>) Access the key-value pair at position. Complexity: O(1). Declaration subscript(position: DictionaryIndex<Key, Value>) -> (Key, Value) { get } subscript(_: Key) Access the value associated with the given key. Reading a key that is not present in self yields nil. Writing nil as the value for a given key erases that key from self. Declaration subscript(key: Key) -> Value? subscript(_: Range<DictionaryIndex<Key, Value>>) Returns a collection representing a contiguous sub-range of self's elements. Complexity: O(1) Declaration subscript(bounds: Range<DictionaryIndex<Key, Value>>) -> Slice<Dictionary<Key, Value>> { get } Declared In CollectionType Instance Methods func contains(_:) Returns true iff an element in self satisfies predicate. Declaration func contains(@noescape predicate: ((Key, Value)) throws -> Bool) rethrows -> Bool Declared In CollectionType, SequenceType func dropFirst() Returns a subsequence containing all but the first element. Complexity: O(1) Declaration func dropFirst() -> Slice<Dictionary<Key, Value>> Declared In CollectionType, SequenceType func dropFirst(_:) Returns a subsequence containing all but the first n elements. Requires: n >= 0 Complexity: O(n) Declaration func dropFirst(n: Int) -> Slice<Dictionary<Key, Value>> 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() -> Slice<Dictionary<Key, Value>> Declared In CollectionType, 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) -> Slice<Dictionary<Key, Value>> 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: ((Key, Value), (Key, Value)) throws -> Bool) rethrows -> Bool Declared In CollectionType, 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<Dictionary<Key, Value>> Declared In CollectionType, SequenceType func filter(_:) Returns an Array containing the elements of self, in order, that satisfy the predicate includeElement. Declaration func filter(@noescape includeElement: ((Key, Value)) throws -> Bool) rethrows -> [(Key, Value)] Declared In CollectionType, SequenceType func flatMap<T>(_: ((Key, Value)) 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: ((Key, Value)) throws -> T?) rethrows -> [T] Declared In CollectionType, SequenceType func flatMap<S : SequenceType>(_: ((Key, Value)) 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: ((Key, Value)) throws -> S) rethrows -> [S.Generator.Element] Declared In CollectionType, 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: ((Key, Value)) throws -> Void) rethrows Declared In CollectionType, SequenceType func generate() Returns a generator over the (key, value) pairs. Complexity: O(1). Declaration func generate() -> DictionaryGenerator<Key, Value> func indexForKey(_:) Returns the Index for the given key, or nil if the key is not present in the dictionary. Declaration func indexForKey(key: Key) -> DictionaryIndex<Key, Value>? 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: ((Key, Value)) throws -> Bool) rethrows -> DictionaryIndex<Key, Value>? Declared In CollectionType 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: ((Key, Value), (Key, Value)) throws -> Bool) rethrows -> Bool Declared In CollectionType, SequenceType func map(_:) Returns an Array containing the results of mapping transform over self. Complexity: O(N). Declaration func map<T>(@noescape transform: ((Key, Value)) 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: ((Key, Value), (Key, Value)) throws -> Bool) rethrows -> (Key, Value)? Declared In CollectionType, 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: ((Key, Value), (Key, Value)) throws -> Bool) rethrows -> (Key, Value)? Declared In CollectionType, SequenceType mutating func popFirst() If !self.isEmpty, return the first key-value pair in the sequence of elements, otherwise return nil. Complexity: Amortized O(1) Declaration mutating func popFirst() -> (Key, Value)? 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) -> Slice<Dictionary<Key, Value>> Declared In CollectionType, SequenceType func prefixThrough(_:) Returns prefixUpTo(position.successor()) Complexity: O(1) Declaration func prefixThrough(position: DictionaryIndex<Key, Value>) -> Slice<Dictionary<Key, Value>> Declared In CollectionType func prefixUpTo(_:) Returns self[startIndex..<end] Complexity: O(1) Declaration func prefixUpTo(end: DictionaryIndex<Key, Value>) -> Slice<Dictionary<Key, Value>> 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, (Key, Value)) throws -> T) rethrows -> T Declared In CollectionType, SequenceType mutating func removeAll(keepCapacity:) Removes all elements. Postcondition: capacity == 0 if keepCapacity is false, otherwise the capacity will not be decreased. Invalidates all indices with respect to self. keepCapacity: If true, the operation preserves the storage capacity that the collection has, otherwise the underlying storage is released. The default is false. Complexity: O(self.count). Declaration mutating func removeAll(keepCapacity keepCapacity: Bool = default) mutating func removeAtIndex(_:) Remove the key-value pair at index. Invalidates all indices with respect to self. Complexity: O(self.count). Declaration mutating func removeAtIndex(index: DictionaryIndex<Key, Value>) -> (Key, Value) mutating func removeValueForKey(_:) Remove a given key and the associated value from the dictionary. Returns the value that was removed, or nil if the key was not present in the dictionary. Declaration mutating func removeValueForKey(key: Key) -> Value? func reverse() Returns an Array containing the elements of self in reverse order. Complexity: O(N), where N is the length of self. Declaration func reverse() -> [(Key, Value)] 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: ((Key, Value), (Key, Value)) -> Bool) -> [(Key, Value)] Declared In CollectionType, SequenceType 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: ((Key, Value)) throws -> Bool) rethrows -> [Slice<Dictionary<Key, Value>>] 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: ((Key, Value), (Key, Value)) throws -> Bool) rethrows -> Bool Declared In CollectionType, 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) -> Slice<Dictionary<Key, Value>> Declared In CollectionType, SequenceType func suffixFrom(_:) Returns self[start..<endIndex] Complexity: O(1) Declaration func suffixFrom(start: DictionaryIndex<Key, Value>) -> Slice<Dictionary<Key, Value>> 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 mutating func updateValue(_:forKey:) Update the value stored in the dictionary for the given key, or, if the key does not exist, add a new key-value pair to the dictionary. Returns the value that was replaced, or nil if a new key-value pair was added. Declaration mutating func updateValue(value: Value, forKey key: Key) -> Value?