UnmodifiableMapView<K, V> class Null safety

View of a Map that disallow modifying the map.

A wrapper around a Map that forwards all members to the map provided in the constructor, except for operations that modify the map. Modifying operations throw instead.

final baseMap = <int, String>{1: 'Mars', 2: 'Mercury', 3: 'Venus'};
final unmodifiableMapView = UnmodifiableMapView(baseMap);

// Remove an entry from the original map.
baseMap.remove(3);
print(unmodifiableMapView); // {1: Mars, 2: Mercury}

unmodifiableMapView.remove(1); // Throws.
Inheritance

Constructors

UnmodifiableMapView(Map<K, V> map)

Properties

entries Iterable<MapEntry<K, V>>
The map entries of this.
read-onlyinherited
hashCode int
The hash code for this object.
read-onlyinherited
isEmpty bool
Whether there is no key/value pair in the map.
read-onlyinherited
isNotEmpty bool
Whether there is at least one key/value pair in the map.
read-onlyinherited
keys Iterable<K>
The keys of this.
read-onlyinherited
length int
The number of key/value pairs in the map.
read-onlyinherited
runtimeType Type
A representation of the runtime type of the object.
read-onlyinherited
values Iterable<V>
The values of this.
read-onlyinherited

Methods

addAll(Map<K, V> other) → void
This operation is not supported by an unmodifiable map.
inherited
addEntries(Iterable<MapEntry<K, V>> entries) → void
This operation is not supported by an unmodifiable map.
inherited
cast<RK, RV>() Map<RK, RV>
Provides a view of this map as having RK keys and RV instances, if necessary.
override
clear() → void
This operation is not supported by an unmodifiable map.
inherited
containsKey(Object? key) bool
Whether this map contains the given key.
inherited
containsValue(Object? value) bool
Whether this map contains the given value.
inherited
forEach(void action(K key, V value)) → void
Applies action to each key/value pair of the map.
inherited
map<K2, V2>(MapEntry<K2, V2> transform(K key, V value)) Map<K2, V2>
Returns a new map where all entries of this map are transformed by the given convert function.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
inherited
putIfAbsent(K key, V ifAbsent()) → V
This operation is not supported by an unmodifiable map.
inherited
remove(Object? key) → V?
This operation is not supported by an unmodifiable map.
inherited
removeWhere(bool test(K key, V value)) → void
This operation is not supported by an unmodifiable map.
inherited
toString() String
A string representation of this object.
inherited
update(K key, V update(V value), {V ifAbsent()?}) → V
This operation is not supported by an unmodifiable map.
inherited
updateAll(V update(K key, V value)) → void
This operation is not supported by an unmodifiable map.
inherited

Operators

operator ==(Object other) bool
The equality operator.
inherited
operator [](Object? key) → V?
The value for the given key, or null if key is not in the map.
inherited
operator []=(K key, V value) → void
This operation is not supported by an unmodifiable map.
inherited