JavaScript Array lastIndexOf()
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.
Definition and Usage
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:
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 »
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 |
