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JavaScript indexOf() Method

String Object Reference JavaScript String Object

Definition and Usage

The indexOf() method returns the position of the first occurrence of a specified value in a string.

This method returns -1 if the value to search for never occurs.

Syntax

stringObject.indexOf(searchvalue,fromindex)

Parameter Description
searchvalue Required. Specifies a value to search for
fromindex Optional. Specifies where to start the search

Tips and Notes

Note: The indexOf() method is case sensitive!

Example

Example

Do different searches within a string:

<script type="text/javascript">

var str="Hello world!";
document.write(str.indexOf("Hello") + "<br />");
document.write(str.indexOf("WORLD") + "<br />");
document.write(str.indexOf("world"));

</script>

The output of the code above will be:

0
-1
6

Try it yourself »

String Object Reference JavaScript String Object

From http://www.w3schools.com (Copyright Refsnes Data)