UnmodifiableMapView class - dart:collection library (original) (raw)

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

• Object
• MapView<K, V>
• UnmodifiableMapView

Implemented types

• Map<K, V>

Constructors

UnmodifiableMapView(Map<K, V> map)

Properties

entries → Iterable<MapEntry<K, V>>

The map entries of this Map.

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 Map.

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 Map.

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