TypedArray.prototype.indexOf()
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.
TheindexOf() method ofTypedArray instances returns the first index at which a given element can be found in the typed array, or -1 if it is not present. This method has the same algorithm asArray.prototype.indexOf().
Try it
const uint8 = new Uint8Array([10, 20, 30, 40, 50]);console.log(uint8.indexOf(50));// Expected output: 4// From position 3console.log(uint8.indexOf(20, 3));// Expected output: -1console.log(uint8.indexOf(51));// Expected output: -1Syntax
js
indexOf(searchElement)indexOf(searchElement, fromIndex)Parameters
searchElementElement to locate in the typed array.
fromIndexOptionalZero-based index at which to start searching,converted to an integer.
Return value
The first index ofsearchElement in the typed array;-1 if not found.
Description
SeeArray.prototype.indexOf() for more details. This method is not generic and can only be called on typed array instances.
Examples
Using indexOf()
js
const uint8 = new Uint8Array([2, 5, 9]);uint8.indexOf(2); // 0uint8.indexOf(7); // -1uint8.indexOf(9, 2); // 2uint8.indexOf(2, -1); // -1uint8.indexOf(2, -3); // 0Specifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-%typedarray%.prototype.indexof |