weakMap.delete

The delete() method removes the specified element from a WeakMap object.

Syntax

wm.delete(key);

Parameters

key

Required. The key of the element to remove from the WeakMap object.

Return value

true if an element in the WeakMap object has been removed successfully. false if the key is not found in the WeakMap or if the key is not an object.

Examples

Using the delete method

var wm = new WeakMap();
wm.set(window, 'foo');

wm.delete(window); // Returns true. Successfully removed.

wm.has(window);    // Returns false. The window object is no longer in the WeakMap.

Specifications

Specification	Status	Comment
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'WeakMap.prototype.delete' in that specification.	Standard	Initial definition.
ECMAScript 2017 Draft (ECMA-262) The definition of 'WeakMap.prototype.delete' in that specification.	Draft

Browser compatibility

Firefox-specific notes

• Prior to SpiderMonkey 38 (Firefox 38 / Thunderbird 38 / SeaMonkey 2.35), this method threw a TypeError when the key parameter was not an object. This has been fixed in version 38 and later to return false as per the ES2015 standard (bug 1127827).

See also

• WeakMap