The lastIndexOf() method returns the last index at which a given element can be found in the typed array, or -1 if it is not present. The typed array is searched backwards, starting at fromIndex. This method has the same algorithm as Array.prototype.lastIndexOf(). TypedArray is one of the typed array types here.
TypedArray.prototype.lastIndexOf()
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Syntax
lastIndexOf(searchElement) lastIndexOf(searchElement, fromIndex)
Parameters
-
searchElement -
Element to locate in the typed array.
-
fromIndex -
Optional. The index at which to start searching backwards. Defaults to the typed array's length, i.e. the whole typed array will be searched. If the index is greater than or equal to the length of the typed array, the whole typed array will be searched. If negative, it is taken as the offset from the end of the typed array. Note that even when the index is negative, the typed array is still searched from back to front. If the calculated index is less than 0, -1 is returned, i.e. the typed array will not be searched.
Return value
The last index of the element in the array; -1 if not found.
Description
lastIndexOf compares searchElement to elements of the typed array using strict equality (the same method used by the ===, or triple-equals, operator).
Examples
Using lastIndexOf
var uint8 = new Uint8Array([2, 5, 9, 2]); uint8.lastIndexOf(2); // 3 uint8.lastIndexOf(7); // -1 uint8.lastIndexOf(2, 3); // 3 uint8.lastIndexOf(2, 2); // 0 uint8.lastIndexOf(2, -2); // 0 uint8.lastIndexOf(2, -1); // 3
Specifications
Browser compatibility
| Desktop | Mobile | Server | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | Deno | Node.js | |
lastIndexOf |
45
|
14
|
37
Starting with Firefox 47, this method will no longer return
-0. For example,
new Uint8Array([0]).lastIndexOf(0, -0) will now always return
+0.
|
No
|
32
|
10
|
45
|
45
|
37
Starting with Firefox 47, this method will no longer return
-0. For example,
new Uint8Array([0]).lastIndexOf(0, -0) will now always return
+0.
|
32
|
10
|
5.0
|
1.0
|
4.0.0
|
See also
© 2005–2022 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/lastIndexOf
