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 element from this WeakSet.

Try it

const weakset1 = new WeakSet();
const object1 = {};
weakset1.add(object1);
console.log(weakset1.has(object1));
// Expected output: true
weakset1.delete(object1);
console.log(weakset1.has(object1));
// Expected output: false

Syntax

js
weakSetInstance.delete(value)

Parameters

value

The value to remove from the WeakSet object.

Return value

true if an element 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 the delete() method

js
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

See also