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WeakSet.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 ⁨September 2015⁩.

The delete() method of WeakSet instances removes the specified value from this set, if it is in the set.

Try it

const weakset = new WeakSet();
const object = {};

weakset.add(object);

console.log(weakset.has(object));
// Expected output: true

weakset.delete(object);

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

Syntax

weakSetInstance.delete(value)

Parameters

value: The value to remove from the WeakSet object. Objects are compared by reference, not by value.

Return value

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

Examples

Using delete()

const ws = new WeakSet();
const obj = {};

ws.add(window);

ws.delete(obj); // Returns false. No obj found to be deleted.
ws.delete(window); // Returns true. Successfully removed.

ws.has(window); // Returns false. The window is no longer present in the WeakSet.

Specifications

Specification
ECMAScript® 2026 Language Specification> # sec-weakset.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	34	23	9	36	34	24	9	3.0	37	9	1.0.0	1.0	0.12.0