JavaScript Array lastIndexOf() Method (original) (raw)

Last Updated : 15 Jul, 2024

The JavaScript **Array lastIndexOf() Method is used to find the index of the last occurrence of the search element provided as the argument to the function.

**Syntax:

array.lastIndexOf(element, start)

**Parameters:

This method accepts two parameters as mentioned above and described below:

**Return value:

This method returns the index of the last occurrence of the element. If the element cannot be found in the array, then this method returns -1.

**Example 1: Below is an example of the Array lastIndexOf() method.

javascript `

let name = ['gfg', 'cse', 'geeks', 'portal']; a = name.lastIndexOf('gfg')

// Printing result of method console.log(a);

`

**Output:

0

**Example 2: In this example, the method will be searched for element 2 in that array and return that element index.

javascript `

// Taking input as an array A // having some elements. let A = [1, 2, 3, 4, 5];

// lastIndexOf() method is called to // test whether the searching element // is present in given array or not. a = A.lastIndexOf(2)

// Printing result of method. console.log(a);

`

**Output:

1

**Example 3: In this example, the method will search for the element 9 in that array if not found then return -1.

javascript `

// Taking input as an array A // having some elements. let name = ['gfg', 'cse', 'geeks', 'portal'];

// lastIndexOf() method is called to // test whether the searching element // is present in given array or not. a = name.lastIndexOf('cat')

// Printing result of method console.log(a);

`

**Output:

-1

We have a complete list of Javascript Array methods, to check those please go through this Javascript Array Complete reference article.

**Supported Browsers:

The browsers supported by JavaScript **Array lastIndexOf() method are listed below: