JavaScript indexOf() Method: String Object

Last update on August 19 2022 21:51:08 (UTC/GMT +8 hours)

Description

The indexOf() method returns the index within the calling string object of the first occurrence of the specified value, starting the search at startIndex. It returns -1 if the value is not found.

Version

Implemented in JavaScript 1.0

Syntax

indexOf(searchValue, startIndex)

Parameter

searchValue: A string representing the value to search for.

startIndex : The location in the string to search the specified value. Location value is an integer between 0 and the length of the string. The default value is 0.

Example of String object: indexOf() Method

In the following web document indexOf() method is used to locate values in a given string.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">

<head>

<meta http-equiv="content-type" content="text/html; charset=iso-8859-1" />

<title>JavaScript String object - indexOf() method example</title>

</head>

<body>

<h1 style="color: red">JavaScript String object : indexOf() method</h1>

<hr />

<script type="text/javascript">

//This is done to make the following JavaScript code compatible to XHTML. <![CDATA[

var Str="Brave new world"

document.write("The index of the first w from the beginning is " +

Str.indexOf("w")+"<br />")

document.write("The index of 'new' from the beginning is " +

Str.indexOf("new"))

//]]>

</script>

</body>

</html>

View the example of String object's indexOf method in the browser

Supported Browser

Internet Explorer 7	Firefox 3.6	Google Chrome 7	Safari 5.0.1	Opera 10
Yes	Yes	Yes	Yes	Yes

Previous: JavaScript fromCharCode() Method: String Object
Next: JavaScript italics() Method: String Object