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JavaScript Array indexOf() Method

❮ JavaScript Array Reference

Example

Search an array for the item "Apple":

var fruits = ["Banana", "Orange", "Apple", "Mango"];
var a = fruits.indexOf("Apple");
Try it Yourself »

More "Try it Yourself" examples below.


Definition and Usage

The indexOf() method searches the array for the specified item, and returns its position.

The search will start at the specified position, or at the beginning if no start position is specified, and end the search at the end of the array.

Returns -1 if the item is not found.

If the item is present more than once, the indexOf method returns the position of the first occurence.

Note: The first item has position 0, the second item has position 1, and so on.

Tip: If you want to search from end to start, use the lastIndexOf() method


Browser Support

The numbers in the table specify the first browser version that fully supports the method.

Method
indexOf() Yes 9.0 1.5 Yes Yes

Syntax

array.indexOf(item, start)

Parameter Values

Parameter Description
item Required. The item to search for
start Optional. Where to start the search. Negative values will start at the given position counting from the end, and search to the end.


Technical Details

Return Value: A Number, representing the position of the specified item, otherwise -1
JavaScript Version: ECMAScript 5

More Examples

Example

Search an array for the item "Apple", starting the search at position 4:

var fruits = ["Banana", "Orange", "Apple", "Mango", "Banana", "Orange", "Apple"];
var a = fruits.indexOf("Apple", 4);
Try it Yourself »

❮ JavaScript Array Reference