UnmodifiableMapView<K, V> class

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

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 nonexistent 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