HashMap<K, V> class

An unordered collection of key-value pairs.

In the C++ STL, this matches std::unordered_map. It utilizes a fast hash table under the hood and makes no guarantees about the iteration order of the elements.

Mixed-in types

Constructors

HashMap()
Creates an empty HashMap.
HashMap.from(Map<K, V> other)
Creates a HashMap from an existing Dart Map.

Properties

empty → bool
Returns true if the map is empty.
no setter
first → Pair<K, V>
The first element.
no setterinherited
hashCode → int
The hash code for this object.
no setteroverride
isEmpty → bool
Whether this collection has no elements.
no setterinherited
isNotEmpty → bool
Returns true if the map is not empty.
no setteroverride
iterator → Iterator<Pair<K, V>>
A new Iterator that allows iterating the elements of this Iterable.
no setteroverride
last → Pair<K, V>
The last element.
no setterinherited
length → int
The number of elements in this Iterable.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
single → Pair<K, V>
Checks that this iterable has only one element, and returns that element.
no setterinherited
size → int
Returns the number of elements in the map.
no setter

Methods

any(bool test(Pair<K, V> element)) → bool
Checks whether any element of this iterable satisfies test.
inherited
cast<R>() → Iterable<R>
A view of this iterable as an iterable of R instances.
inherited
clear() → void
Removes all elements from the map.
contains(Object? element) → bool
Whether the collection contains an element equal to element.
inherited
containsKey(K key) → bool
Returns true if the map contains the specified key.
elementAt(int index) → Pair<K, V>
Returns the indexth element.
inherited
erase(K key) → bool
Removes the element with the specified key.
every(bool test(Pair<K, V> element)) → bool
Checks whether every element of this iterable satisfies test.
inherited
expand<T>(Iterable<T> toElements(Pair<K, V> element)) → Iterable<T>
Expands each element of this Iterable into zero or more elements.
inherited
firstWhere(bool test(Pair<K, V> element), {Pair<K, V> orElse()?}) → Pair<K, V>
The first element that satisfies the given predicate test.
inherited
fold<T>(T initialValue, T combine(T previousValue, Pair<K, V> element)) → T
Reduces a collection to a single value by iteratively combining each element of the collection with an existing value
inherited
followedBy(Iterable<Pair<K, V>> other) → Iterable<Pair<K, V>>
Creates the lazy concatenation of this iterable and other.
inherited
forEach(void action(Pair<K, V> element)) → void
Invokes action on each element of this iterable in iteration order.
inherited
insert(K key, V value) → void
Inserts a key-value pair. If the key already exists, its value is updated.
join([String separator = ""]) → String
Converts each element to a String and concatenates the strings.
inherited
lastWhere(bool test(Pair<K, V> element), {Pair<K, V> orElse()?}) → Pair<K, V>
The last element that satisfies the given predicate test.
inherited
map<T>(T toElement(Pair<K, V> e)) → Iterable<T>
The current elements of this iterable modified by toElement.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
reduce(Pair<K, V> combine(Pair<K, V> value, Pair<K, V> element)) → Pair<K, V>
Reduces a collection to a single value by iteratively combining elements of the collection using the provided function.
inherited
singleWhere(bool test(Pair<K, V> element), {Pair<K, V> orElse()?}) → Pair<K, V>
The single element that satisfies test.
inherited
skip(int count) → Iterable<Pair<K, V>>
Creates an Iterable that provides all but the first count elements.
inherited
skipWhile(bool test(Pair<K, V> value)) → Iterable<Pair<K, V>>
Creates an Iterable that skips leading elements while test is satisfied.
inherited
swap(HashMap<K, V> other) → void
Exchanges the contents of this map with those of other.
take(int count) → Iterable<Pair<K, V>>
Creates a lazy iterable of the count first elements of this iterable.
inherited
takeWhile(bool test(Pair<K, V> value)) → Iterable<Pair<K, V>>
Creates a lazy iterable of the leading elements satisfying test.
inherited
toList({bool growable = true}) → List<Pair<K, V>>
Creates a List containing the elements of this Iterable.
inherited
toSet() → Set<Pair<K, V>>
Creates a Set containing the same elements as this iterable.
inherited
toString() → String
Returns a string representation of (some of) the elements of this.
inherited
where(bool test(Pair<K, V> element)) → Iterable<Pair<K, V>>
Creates a new lazy Iterable with all elements that satisfy the predicate test.
inherited
whereType<T>() → Iterable<T>
Creates a new lazy Iterable with all elements that have type T.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
override
operator [](K key) → V?
Returns the value associated with the key, or null if it doesn't exist.
operator []=(K key, V value) → void
Associates the value with the key.