LinkedHashMap<K, V> class

A hash-table based implementation of Map.

The insertion order of keys is remembered, and keys are iterated in the order they were inserted into the map. Values are iterated in their corresponding key's order. Changing a key's value, when the key is already in the map, does not change the iteration order, but removing the key and adding it again will make it be last in the iteration order.

The keys of a LinkedHashMap must have consistent Object.== 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 ==.

Implemented types

Constructors

LinkedHashMap({bool equals(K, K), int hashCode(K), bool isValidKey(dynamic)})
factory
Creates an insertion-ordered hash-table based Map. [...]
LinkedHashMap.from(Map other)
factory
Creates a LinkedHashMap that contains all key value pairs of other. [...]
LinkedHashMap.fromEntries(Iterable<MapEntry<K, V>> entries)
factory
Creates a LinkedHashMap containing the entries of entries. [...]
LinkedHashMap.fromIterable(Iterable iterable, {K key(dynamic element), V value(dynamic element)})
factory
Creates a LinkedHashMap where the keys and values are computed from the iterable. [...]
LinkedHashMap.fromIterables(Iterable<K> keys, Iterable<V> values)
factory
Creates a LinkedHashMap associating the given keys to values. [...]
LinkedHashMap.identity()
factory
Creates an insertion-ordered identity-based map. [...]
LinkedHashMap.of(Map<K, V> other)
factory
Creates a LinkedHashMap that contains all key value pairs of other.

Properties

entriesIterable<MapEntry<K, V>>
read-only, inherited
The map entries of this.
hashCodeint
read-only, inherited
The hash code for this object. [...]
isEmptybool
read-only, inherited
Whether there is no key/value pair in the map.
isNotEmptybool
read-only, inherited
Whether there is at least one key/value pair in the map.
keysIterable<K>
read-only, inherited
The keys of this. [...]
lengthint
read-only, inherited
The number of key/value pairs in the map.
runtimeTypeType
read-only, inherited
A representation of the runtime type of the object.
valuesIterable<V>
read-only, inherited
The values of this. [...]

Methods

addAll(Map<K, V> other) → void
inherited
Adds all key/value pairs of other to this map. [...]
addEntries(Iterable<MapEntry<K, V>> newEntries) → void
inherited
Adds all key/value pairs of newEntries to this map. [...]
cast<RK, RV>() → Map<RK, RV>
inherited
Provides a view of this map as having RK keys and RV instances, if necessary. [...]
clear() → void
inherited
Removes all entries from the map. [...]
containsKey(Object? key) → bool
inherited
Whether this map contains the given key. [...]
containsValue(Object? value) → bool
inherited
Whether this map contains the given value. [...]
forEach(void action(K key, V value)) → void
inherited
Applies action to each key/value pair of the map. [...]
map<K2, V2>(MapEntry<K2, V2> convert(K key, V value)) → Map<K2, V2>
inherited
Returns a new map where all entries of this map are transformed by the given convert function.
noSuchMethod(Invocation invocation) → dynamic
inherited
Invoked when a non-existent method or property is accessed. [...]
putIfAbsent(K key, V ifAbsent()) → V
inherited
Look up the value of key, or add a new entry if it isn't there. [...]
remove(Object? key) → V?
inherited
Removes key and its associated value, if present, from the map. [...]
removeWhere(bool test(K key, V value)) → void
inherited
Removes all entries of this map that satisfy the given test.
toString() → String
inherited
A string representation of this object. [...]
update(K key, V update(V value), {V ifAbsent()}) → V
inherited
Updates the value for the provided key. [...]
updateAll(V update(K key, V value)) → void
inherited
Updates all values. [...]

Operators

operator ==(Object other) → bool
inherited
The equality operator. [...]
operator [](Object? key) → V?
inherited
The value for the given key, or null if key is not in the map. [...]
operator []=(K key, V value) → void
inherited
Associates the key with the given value. [...]

© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dart.dev/stable/2.13.0/dart-collection/LinkedHashMap-class.html