TopLevel
Class WeakMap
Object
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 Versioned:
From version 21.2.
Properties
size  :  Number
Number of key/value pairs stored in this map.
Constructor Summary
WeakMap()
Creates an empty map.
WeakMap(values : Iterable)
If the passed value is null or undefined then an empty map is constructed.
Method Summary
clear() : void
Removes all key/value pairs from this map.
delete(key : Object) : boolean
Removes the entry for the given key.
get(key : Object) : Object
Returns the value associated with the given key.
has(key : Object) : boolean
Returns if this map has value associated with the given key.
set(key : Object, value : Object) : WeakMap
Adds or updates a key/value pair to the map.
Constructor Detail
WeakMap
public WeakMap()
Creates an empty map.

WeakMap
public 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 Detail
clear
clear() : void
Removes all key/value pairs from this map.

delete
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
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
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
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:
This map object.