TypedArray.prototype.keys()

The keys() method of {{jsxref("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 {{jsxref("Array.prototype.keys()")}}.

{{InteractiveExample("JavaScript Demo: TypedArray.prototype.keys()")}}

```js interactive-example 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

```js-nolint
keys()

Parameters#

None.

Return value#

A new iterable iterator object.

Description#

See {{jsxref("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#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• Polyfill of TypedArray.prototype.keys in core-js
• JavaScript typed arrays guide
• {{jsxref("TypedArray")}}
• {{jsxref("TypedArray.prototype.entries()")}}
• {{jsxref("TypedArray.prototype.values()")}}
• TypedArray.prototype[Symbol.iterator]()
• {{jsxref("Array.prototype.keys()")}}
• Iteration protocols