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TypedArray.prototype.keys()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨September 2016⁩.

The keys() method of TypedArray instances returns a new array iterator object that contains the keys for each index in the typed array. This method has the same algorithm as Array.prototype.keys().

Try it

const uint8 = new Uint8Array([10, 20, 30, 40, 50]);
const keys = uint8.keys();

keys.next();
keys.next();

console.log(keys.next().value);
// Expected output: 2

Syntax

keys()

Parameters

None.

Return value

A new iterable iterator object.

Description

See Array.prototype.keys() for more details. This method is not generic and can only be called on typed array instances.

Examples

Iteration using for...of loop

const arr = new Uint8Array([10, 20, 30, 40, 50]);
const arrKeys = arr.keys();
for (const n of arrKeys) {
  console.log(n);
}

Alternative iteration

const arr = new Uint8Array([10, 20, 30, 40, 50]);
const arrKeys = arr.keys();
console.log(arrKeys.next().value); // 0
console.log(arrKeys.next().value); // 1
console.log(arrKeys.next().value); // 2
console.log(arrKeys.next().value); // 3
console.log(arrKeys.next().value); // 4

Specifications

Specification
ECMAScript® 2026 Language Specification> # sec-%typedarray%.prototype.keys>

Browser compatibility

	Desktop					Mobile							Server
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	WebView Android	WebView on iOS	Bun	Deno	Node.js
`keys`	38	12	37	25	10	38	37	25	10	3.0	38	10	1.0.0	1.0	0.12.0