WeakMap.prototype.delete()

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

{{InteractiveExample("JavaScript Demo: WeakMap.prototype.delete()")}}

```js interactive-example 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

```js-nolint
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#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• {{jsxref("WeakMap")}}
• {{jsxref("WeakMap.prototype.get()")}}
• {{jsxref("WeakMap.prototype.set()")}}
• {{jsxref("WeakMap.prototype.has()")}}