AsyncIterator.prototype[Symbol.asyncIterator]()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since January 2020.

The [Symbol.asyncIterator]() method of AsyncIterator instances implements the async iterable protocol and allows built-in async iterators to be consumed by most syntaxes expecting async iterables, such as for await...of loops. It returns the value of this, which is the async iterator object itself.

Syntax

js
asyncIterator[Symbol.asyncIterator]()

Parameters

None.

Return value

The value of this, which is the async iterator object itself.

Examples

Iteration using for await...of loop

Note that you seldom need to call this method directly. The existence of the [Symbol.asyncIterator]() method makes all built-in async iterators async iterable, and iterating syntaxes like the for await...of loop automatically calls this method to obtain the async iterator to loop over.

js
const asyncIterator = (async function* () {
  yield 1;
  yield 2;
  yield 3;
})();
(async () => {
  for await (const value of asyncIterator) {
    console.log(value);
  }
})();
// Logs: 1, 2, 3

Specifications

Specification
ECMAScript Language Specification
# sec-asynciteratorprototype-asynciterator

Browser compatibility

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See also