WeakMap.prototype.delete()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It's been available across browsers since July 2015.

The delete() method of WeakMap instances removes the entry specified by the key from this WeakMap.

Try it

const weakmap = new WeakMap();
const object = {};

weakmap.set(object, 42);

console.log(weakmap.delete(object));
// Expected output: true

console.log(weakmap.has(object));
// Expected output: false

Syntax

weakMapInstance.delete(key)

Parameters

key: The key of the entry to remove from the WeakMap object. Object keys are compared by reference, not by value.

Return value

true if an entry in the WeakMap object has been removed successfully. false if the key is not found in the WeakMap. Always returns false if key is not an object or a non-registered symbol.

Examples

Using delete()

const 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® 2027 Language Specification # sec-weakmap.prototype.delete

Browser compatibility

	Desktop					Mobile							Server
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS	Bun	Deno	Node.js
`delete`	36	12	6 Before 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.	23	8	36	6 Before Firefox for Android 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.	24	8	3.0	37	8	1.0.0	1.0	0.12.0