Web/JavaScript/Reference/Global objects/WeakMap/delete

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

Syntax

wm.delete(key);

Parameters

key: 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
ECMAScript (ECMA-262)The definition of 'WeakMap.prototype.delete' in that specification.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
`delete`	Chrome Full support 36	Edge Full support 12	Firefox Full support 6 Notes' Full support 6 Notes' Notes' Prior to Firefox 38, 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.	IE Full support 11	Opera Full support 23	Safari Full support 8	WebView Android Full support 37	Chrome Android Full support 36	Firefox Android Full support 6 Notes' Full support 6 Notes' Notes' Prior to Firefox 38, 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.	Opera Android Full support 24	Safari iOS Full support 8	Samsung Internet Android Full support 3.0	nodejs Full support 0.12 Full support 0.12 Full support 0.10 Disabled' Disabled' From version 0.10: this feature is behind the `--harmony` runtime flag.

Legend

Full support: Full support
See implementation notes.': See implementation notes.
User must explicitly enable this feature.': User must explicitly enable this feature.