Lessons
HTML
- HTML HOME
- HTML Introduction
- HTML Editors
- HTML Basic
- HTML Elements
- HTML Attributes
- HTML Headings
- HTML Paragraphs
- HTML Styles
- HTML Formatting
- HTML Quotations
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- HTML Colors
- HTML CSS
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- HTML Blocks
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- HTML Id
- HTML Iframes
- HTML JavaScript
- HTML File Paths
- HTML Head
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- HTML Responsive
- HTML Computercode
- HTML Entities
- HTML Symbols
- HTML Charset
- HTML URL Encode
- HTML XHTML
HTML5
HTML Graphics
HTML Media
HTML APIs
HTML Examples
HTML References
- HTML Tag List
- HTML Attributes
- HTML Events
- HTML Colors
- HTML Canvas
- HTML Audio/Video
- HTML Doctypes
- HTML Character Sets
- HTML URL Encode
- HTML Lang Codes
- HTML Messages
- HTML Methods
- PX to Em Converter
- Keyboard Shortcuts
HTML Forms
HTML JavaScript
HTML JavaScript
JavaScript makes HTML pages more dynamic and interactive.
Example
My First JavaScript
The HTML <script> Tag
The <script> tag is used to define a client-side script (JavaScript).
The <script> element either contains scripting statements, or it points to an external script file through the src attribute.
Common uses for JavaScript are image manipulation, form validation, and dynamic changes of content.
To select an HTML element, JavaScript very often use the document.getElementById() method.
This JavaScript example writes "Hello JavaScript!" into an HTML element with id="demo":
Example
<script>
document.getElementById("demo").innerHTML = "Hello JavaScript!";
</script>Tip: You can learn much more about JavaScript in our JavaScript Tutorial.
A Taste of JavaScript
Here are some examples of what JavaScript can do:
JavaScript can change HTML content
document.getElementById("demo").innerHTML = "Hello JavaScript!";JavaScript can change HTML styles
document.getElementById("demo").style.fontSize = "25px";
document.getElementById("demo").style.color = "red";
document.getElementById("demo").style.backgroundColor = "yellow";JavaScript can change HTML attributes
document.getElementById("image").src = "picture.gif";The HTML <noscript> Tag
The <noscript> tag is used to provide an alternate content for users that have disabled scripts in their browser or have a browser that doesn't support client-side scripts:
Example
<script>
document.getElementById("demo").innerHTML = "Hello JavaScript!";
</script>
<noscript>Sorry, your browser does not support JavaScript!</noscript>HTML Script Tags
| Tag | Description |
|---|---|
| <script> | Defines a client-side script |
| <noscript> | Defines an alternate content for users that do not support client-side scripts |