TypedArray.prototype.keys()

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

Browser compatibility

See also

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