Class WeakMap
The WeakMap is map whose entries are subject to garbage collection if there are no more references to the keys.
Keys must be objects (no primitives). Elements can’t be iterated.
API Version:
Available from version 21.2.
Property Summary
Property Description size : Number Number of key/value pairs stored in this map.
Constructor Summary
Constructor Description WeakMap ()Creates an empty map. WeakMap (Iterable )If the passed value is null or undefined then an empty map is constructed.
Method Summary
Method Description clear ()Removes all key/value pairs from this map. delete (Object )Removes the entry for the given key. get (Object )Returns the value associated with the given key. has (Object )Returns if this map has value associated with the given key. set (Object , Object )Adds or updates a key/value pair to the map.
Methods inherited from class Object
assign , create , create , defineProperties , defineProperty , entries , freeze , fromEntries , getOwnPropertyDescriptor , getOwnPropertyNames , getOwnPropertySymbols , getPrototypeOf , hasOwnProperty , is , isExtensible , isFrozen , isPrototypeOf , isSealed , keys , preventExtensions , propertyIsEnumerable , seal , setPrototypeOf , toLocaleString , toString , valueOf , values
Property Details
size
size: Number
Number of key/value pairs stored in this map.
Constructor Details
WeakMap()
WeakMap()
Creates an empty map.
WeakMap(Iterable)
WeakMap(values: Iterable )
If the passed value is null or undefined then an empty map is constructed. Else an iterator object is expected
that produces a two-element array-like object whose first element is a value that will be used as a Map key and
whose second element is the value to associate with that key.
Parameters:
values - The initial map values
Method Details
clear()
clear(): void
Removes all key/value pairs from this map.
delete(Object)
delete(key: Object ): Boolean
Removes the entry for the given key.
Parameters:
key - The key of the key/value pair to be removed from the map.
Returns:
true if the map contained an entry for the passed key that was removed. Else false is returned.
get(Object)
get(key: Object ): Object
Returns the value associated with the given key.
Parameters:
key - The key to look for.
Returns:
The value associated with the given key if an entry with the key exists else undefined is returned.
has(Object)
has(key: Object ): Boolean
Returns if this map has value associated with the given key.
Parameters:
key - The key to look for.
Returns:
true if an entry with the key exists else false is returned.
set(Object, Object)
set(key: Object , value: Object ): WeakMap
Adds or updates a key/value pair to the map.
Parameters:
key - The key object.
value - The value to be associate with the key.
Returns:
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