JS & DOM Reference
OverviewJavaScript Objects
JS ArrayJS Boolean
JS Date
JS Math
JS Number
JS String
JS RegExp
JS Global
Browser Objects
WindowNavigator
Screen
History
Location
Core DOM Objects
DOM NodeDOM NodeList
DOM NamedNodeMap
DOM Document
DOM Element
DOM Attr
HTML DOM Objects
DOM DocumentDOM Events
DOM Elements
DOM Anchor
DOM Area
DOM Base
DOM Body
DOM Button
DOM Form
DOM Frame/IFrame
DOM Frameset
DOM Image
DOM Input Button
DOM Input Checkbox
DOM Input File
DOM Input Hidden
DOM Input Password
DOM Input Radio
DOM Input Reset
DOM Input Submit
DOM Input Text
DOM Link
DOM Meta
DOM Object
DOM Option
DOM Select
DOM Style
DOM Table
DOM td / th
DOM tr
DOM Textarea
JavaScript indexOf() Method
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
| Parameter | Description |
|---|---|
| searchstring | Required. The string to search for |
| start | Optional. The start position in the string to start the search. If omitted, the search starts from position 0 |
Browser Support
The indexOf() method is supported in all major browsers.
Tips and Notes
Note: The indexOf() method is case sensitive!
Tip: Also look at the lastIndexOf() method.
Examples
Example 1
Do different searches within a string:
var str="Hello world!";
document.write(str.indexOf("d") + "<br />");
document.write(str.indexOf("WORLD") + "<br />");
document.write(str.indexOf("world"));
</script>
The output of the code above will be:
-1
6
Try it yourself »
Example 2
Differences between indexOf and lastIndexOf:
var str="I love W3Schools!"
document.write("Index of first o: " + str.indexOf("o"))
document.write("<br />")
document.write("Index of last o: " + str.lastIndexOf("o"))
document.write("<br />")
document.write("Index of first 'love': " + str.indexOf("love"))
document.write("<br />")
document.write("Index of last 'love': " + str.lastIndexOf("love"))
</script>
The output of the code above will be:
Index of last o: 13
Index of first 'love': 2
Index of last 'love': 2
Try it yourself »
JavaScript String Object
W3Schools' Online Certification
The perfect solution for professionals who need to balance work, family, and career building.
More than 10 000 certificates already issued!
The HTML Certificate documents your knowledge of HTML.
The CSS Certificate documents your knowledge of advanced CSS.
The JavaScript Certificate documents your knowledge of JavaScript and HTML DOM.
The jQuery Certificate documents your knowledge of jQuery.
The XML Certificate documents your knowledge of XML, XML DOM and XSLT.
The ASP Certificate documents your knowledge of ASP, SQL, and ADO.
The PHP Certificate documents your knowledge of PHP and SQL (MySQL).
| WEB HOSTING |
|---|
| Best Web Hosting |
| PHP MySQL Hosting |
| Best Hosting Coupons |
| UK Reseller Hosting |
| Cloud Hosting |
| Top Web Hosting |
| $7.95/mo SEO Hosting |
| Premium Website Design |
| WEB BUILDING |
|---|
| Download XML Editor |
| FREE Website BUILDER |
| Free Website Templates Free CSS Templates |
| Make Your Own Website |
| W3SCHOOLS EXAMS |
|---|
|
Get Certified in: HTML, CSS, JavaScript, XML, PHP, and ASP |
| W3SCHOOLS BOOKS |
|---|
|
New Books: HTML, CSS JavaScript, and Ajax |
| STATISTICS |
|---|
|
Browser Statistics Browser OS Browser Display |
| SHARE THIS PAGE |
|---|
Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content.
While using this site, you agree to have read and accepted our terms of use and privacy policy.
Copyright 1999-2012 by Refsnes Data. All Rights Reserved.