JavaScript How To ...

Use the <script> tag to insert a JavaScript in an HTML document.

Examples

Write text
How to write text on a page

Write text with formatting
How to format the text on your page with HTML tags

How to Put a JavaScript Into an HTML Document

<html>
<head>
</head>
<body>
<script type="text/javascript">
document.write("Hello World!")
</script>
</body>
</html>

And it produces this output:

Hello World!

To insert a script in an HTML document, use the <script> tag. Use the type attribute to define the scripting language.

<script type="text/javascript">

Then comes the JavaScript: In JavaScript the command for writing some text on a page is document.write:

document.write("Hello World!")

The script ends:

</script>

Ending Statements with a Semicolon?

With the traditional programming languages C++ and Java, each code statement has to end with a semicolon.

Many programmers continue this habit when writing JavaScript, but in general, semicolons are optional and are required only if you want to put more than one statement on a single line.

How to Handle Older Browsers

Older browsers that do not support scripts will display the script as page content. To prevent them from doing this, you can use the HTML comment tag:

<script type="text/javascript">
<!--
    some statements
//-->
</script>

The two forward slashes in front of the end of comment line (//) are a JavaScript comment symbol, and prevent the JavaScript from trying to compile the line.

Note that you can't put // in front of the first comment line (like //<!--), because older browsers will display it. Funny? Yes! But that's the way it is.

Computer Joke

My Grandmother: "I can't find my sloppy disk!"

Jump to: Top of Page or HOME or Printer friendly page

Search W3Schools:

What Others Say About Us

Does the world know about us? Check out these places:

Dogpile Alta Vista MSN Google Excite Lycos Yahoo Ask Jeeves

We Help You For Free. You Can Help Us!

W3Schools is for training only. We do not warrant its correctness or its fitness for use. The risk of using it remains entirely with the user. While using this site, you agree to have read and accepted our terms of use and privacy policy.

How we converted to XHTML

Domain Name
Registration & More!

Your own Web Site?

Read W3Schools
Hosting Tutorial

ASP Hosting
ASP.net Hosting
Web Hosting

$15 Domain Name
Registration
Save $20 / year!

Advertise
at W3Schools

Only 0.5 CPM

SELECTED LINKS

Books Online

Web Software

The Future of
Web Development

Jobs and Careers

Web Security
Web Statistics
Web Standards

PARTNERS

W3Schools
TopXML
VisualBuilder
XMLPitstop
DevelopersDex
DevGuru
Programmers Heaven
The Code Project
Tek Tips Forum
ZVON.ORG
TopXML Search