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JavaScript Array lastIndexOf()

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Examples

Find the last index of "Apple":

const fruits = ["Apple", "Orange", "Apple", "Mango"];
let index = fruits.lastIndexOf("Apple");
Try it Yourself »

More than one apple:

const fruits = ["Orange", "Apple", "Mango", "Apple", "Banana", "Apple"];
let index = fruits.lastIndexOf("Apple");
Try it Yourself »

More examples below.

Description

The lastIndexOf() method returns the last index (position) of a specified value.

The lastIndexOf() method returns -1 if the value is not found.

The lastIndexOf() starts at a specified index and searches from right to left.

By defalt the search starts at the last element and ends at the first.

Negative start values counts from the last element (but still searches from right to left).

See Also:

indexOf()

Syntax

array.lastIndexOf( item, start)

Parameters

Parameter Description
item Required.
The value to search for.
start Optional.
Where to start the search.
Default is the last element (array.length-1).
Negative start values counts from the last element (but still searches from right to left).

Return Value

Type Description
A number The position of the specified item.
-1 if the item is not found.

More Examples

Start the search at position 4:

const fruits = ["Orange", "Apple", "Mango", "Apple", "Banana", "Apple"];
let index = fruits.lastIndexOf("Apple", 4);
Try it Yourself »

Start the search at the second last position:

const fruits = ["Orange", "Apple", "Mango", "Apple", "Banana", "Apple"];
let index = fruits.lastIndexOf("Apple", -2);
Try it Yourself »

Related Pages:

Array Tutorial

Array Const

Array Methods

Array Sort

Array Iterations

Browser Support

lastIndexOf() is an ECMAScript5 (ES5) feature.

ES5 (JavaScript 2009) fully supported in all browsers:

Chrome Edge Firefox Safari Opera IE
Yes Yes Yes Yes Yes 9-11


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