WeakRef.prototype.deref()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since April 2021.

The deref() method of WeakRef instances returns this WeakRef's target value, or undefined if the target value has been garbage-collected.

Syntax

js
deref()

Parameters

None.

Return value

The target value of the WeakRef, which is either an object or a non-registered symbol. Returns undefined if the value has been garbage-collected.

Description

See the Notes on WeakRefs section of the WeakRef page for some important notes.

Examples

Using deref()

See the Examples section of the WeakRef page for the complete example.

js
const tick = () => {
  // Get the element from the weak reference, if it still exists
  const element = this.ref.deref();
  if (element) {
    element.textContent = ++this.count;
  } else {
    // The element doesn't exist anymore
    console.log("The element is gone.");
    this.stop();
    this.ref = null;
  }
};

Specifications

Specification
ECMAScript® 2025 Language Specification
# sec-weak-ref.prototype.deref

Browser compatibility

BCD tables only load in the browser

See also