description

# 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
  - 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