The indexOf()
method 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 as Array.prototype.indexOf()
. TypedArray is one of the typed array types here.
Syntax
typedarray.indexOf(searchElement[, fromIndex = 0])
Parameters
searchElement
- Element to locate in the typed array.
fromIndex
- The index to start the search at. If the index is greater than or equal to the typed array's length, -1 is returned, which means the typed array will not be searched. If the provided index value is a negative number, it is taken as the offset from the end of the typed array. Note: if the provided index is negative, the typed array is still searched from front to back. If the calculated index is less than 0, then the whole typed array will be searched. Default: 0 (entire typed array is searched).
Return value
The first index of the element in the array; -1 if not found.
Description
indexOf
compares searchElement
to elements of the typed array using strict equality (the same method used by the ===, or triple-equals, operator).
Examples
var uint8 = new Uint8Array([2, 5, 9]); uint8.indexOf(2); // 0 uint8.indexOf(7); // -1 uint8.indexOf(9, 2); // 2 uint8.indexOf(2, -1); // -1 uint8.indexOf(2, -3); // 0
Specifications
Specification | Status | Comment |
---|---|---|
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'TypedArray.prototype.indexOf' in that specification. |
Standard | Initial definition. |
ECMAScript Latest Draft (ECMA-262) The definition of 'TypedArray.prototype.indexOf' in that specification. |
Living Standard |
Browser compatibility
Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | 45 | Yes | 371 | No | 32 | No |
Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS Safari |
---|---|---|---|---|---|---|---|
Basic support | No | 45 | Yes | 371 | No | 32 | No |
1. Starting with Firefox 47, this method will no longer return -0
. For example, new Uint8Array([0]).indexOf(0, -0)
will now always return +0
.