Dictionary

A hash-based mapping from Key to Value instances. Also a collection of key-value pairs with no defined ordering.

Inheritance CollectionType, DebugPrintable, DictionaryLiteralConvertible, Printable, Reflectable, SequenceType, _CollectionType, _SequenceType, _Sequence_Type View Protocol Hierarchy →
Associated Types
  • Element = (Key, Value)

Type alias inferred.

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 isEmpty: Bool

True iff count == 0

Declaration

  • var isEmpty: Bool { get }
var keys: LazyForwardCollection<MapCollectionView<[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 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 values: LazyForwardCollection<MapCollectionView<[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

Subscripts

subscript(_: Key)

Declaration

  • subscript(key: Key) -> Value?
subscript(_: DictionaryIndex<Key, Value>)

Declaration

Instance Methods

func generate()

Return a generator over the (key, value) pairs.

Complexity: O(1)

Declaration

func getMirror()

Returns a mirror that reflects self.

Declaration

func indexForKey(_:)

Returns the Index for the given key, or nil if the key is not present in the dictionary.

Declaration

mutating func removeAll(_:)

Remove 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(count).

Declaration

  • mutating func removeAll(keepCapacity: Bool = default)
mutating func removeAtIndex(_:)

Remove the key-value pair at index i

Invalidates all indices with respect to self.

Complexity: O(count).

Declaration

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?
mutating func updateValue(_:forKey:)

Update the value stored in the dictionary for the given key, or, if they 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?