HashMap<K, V> class

A hash-table based implementation of Map.

A hash-table based implementation of Map.

The keys of a HashMap must have consistent Object.operator== and Object.hashCode implementations. This means that the == operator must define a stable equivalence relation on the keys (reflexive, symmetric, transitive, and consistent over time), and that hashCode must be the same for objects that are considered equal by ==.

The map allows null as a key.

Iterating the map's keys, values or entries (through forEach) may happen in any order. The itearation order only changes when the map is modified. Values are iterated in the same order as their associated keys, so iterating the keys and values in parallel will give matching key and value pairs.

Implements
Implemented by

Constructors

HashMap({bool equals(K key1, K key2), int hashCode(K key), bool isValidKey(potentialKey)})
Creates an unordered hash-table based Map.
HashMap.identity()
Creates an unordered identity-based map.
HashMap.from(Map other)
Creates a HashMap that contains all key/value pairs of other.
HashMap.fromIterable(Iterable iterable, {K key(element), V value(element)})
Creates a HashMap where the keys and values are computed from the iterable.
HashMap.fromIterables(Iterable<K> keys, Iterable<V> values)
Creates a HashMap associating the given keys to values.

Instance Properties

isEmpty bool Inherited
read-only
keys Iterable<K> Inherited
read-only
values Iterable<V> Inherited
read-only
isNotEmpty bool Inherited
read-only
length int Inherited
read-only

Instance Methods

containsValue(Object value) → bool Inherited
Returns true if this map contains the given value.
remove(Object key) → V Inherited
Removes key and its associated value, if present, from the map.
clear() → void Inherited
Removes all pairs from the map.
containsKey(Object key) → bool Inherited
Returns true if this map contains the given key.
addAll(Map<K,V> other) → void Inherited
Adds all key-value pairs of other to this map.
forEach(void f(K key, V value)) → void Inherited
Applies f to each key-value pair of the map.
putIfAbsent(K key, V ifAbsent()) → V Inherited
Look up the value of key, or add a new value if it isn't there.

Operators

operator []=(K key, V value) → void Inherited
Associates the key with the given value.
operator [](Object key) → V Inherited
Returns the value for the given key or null if key is not in the map.