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
js
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
js
const arr = new Uint8Array([10, 20, 30, 40, 50]);
const arrKeys = arr.keys();
for (const n of arrKeys) {
console.log(n);
}
Alternative iteration
js
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® 2025 Language Specification # sec-%typedarray%.prototype.keys |