struct Dictionary<Key : Hashable, Value>
Inheritance |
CollectionType, CustomDebugStringConvertible, CustomStringConvertible, DictionaryLiteralConvertible, Indexable, SequenceType, _ObjectiveCBridgeable, _Reflectable
View Protocol Hierarchy →
|
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Associated Types | |
Import | import Swift |
Initializers
Create an instance initialized with elements
.
Declaration
init(dictionaryLiteral elements: (Key, Value)...)
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
The number of entries in the dictionary.
Complexity: O(1).
Declaration
var count: Int { get }
A textual representation of self
, suitable for debugging.
Declaration
var debugDescription: String { get }
A textual representation of self
.
Declaration
var description: String { get }
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 }
Returns the first element of self
, or nil
if self
is empty.
Complexity: O(1)
Declaration
var first: (Key, Value)? { 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
var indices: Range<DictionaryIndex<Key, Value>> { get }
Declared In
CollectionType
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 }
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
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 }
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
Access the key-value pair at position
.
Complexity: O(1).
Declaration
subscript(position: DictionaryIndex<Key, Value>) -> (Key, Value) { get }
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?
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
Returns true
iff an element in self
satisfies predicate
.
Declaration
func contains(@noescape predicate: ((Key, Value)) throws -> Bool) rethrows -> Bool
Declared In
CollectionType
, SequenceType
Returns a subsequence containing all but the first element.
Complexity: O(1)
Declaration
func dropFirst() -> Slice<Dictionary<Key, Value>>
Declared In
CollectionType
, SequenceType
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
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
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
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
Returns a lazy SequenceType
containing pairs (n, x), where
ns are consecutive Int
s 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
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
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
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
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
Returns a generator over the (key, value) pairs.
Complexity: O(1).
Declaration
func generate() -> DictionaryGenerator<Key, Value>
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>?
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
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
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
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
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
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)?
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
Returns prefixUpTo(position.successor())
Complexity: O(1)
Declaration
func prefixThrough(position: DictionaryIndex<Key, Value>) -> Slice<Dictionary<Key, Value>>
Declared In
CollectionType
Returns self[startIndex..<end]
Complexity: O(1)
Declaration
func prefixUpTo(end: DictionaryIndex<Key, Value>) -> Slice<Dictionary<Key, Value>>
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
func reduce<T>(initial: T, @noescape combine: (T, (Key, Value)) throws -> T) rethrows -> T
Declared In
CollectionType
, SequenceType
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)
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)
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?
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
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
Returns the maximal SubSequence
s of self
, in order, that
don't contain elements satisfying the predicate isSeparator
.
maxSplit
: The maximum number of SubSequence
s to
return, minus 1.
If maxSplit + 1
SubSequence
s 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
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
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
Returns self[start..<endIndex]
Complexity: O(1)
Declaration
func suffixFrom(start: DictionaryIndex<Key, Value>) -> Slice<Dictionary<Key, Value>>
Declared In
CollectionType
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
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?
A hash-based mapping from
Key
toValue
instances. Also a collection of key-value pairs with no defined ordering.