WeakRef.prototype.deref()

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

undefined

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

See also