HTML JavaScript

Education is not limited to just classrooms. It can be gained anytime, anywhere... - Ravi Ranjan (M.Tech-NIT)

JavaScript makes HTML pages more dynamic and interactive.

Example

My First JavaScript

Click me to display Date and Time

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(id) method.

This JavaScript example writes "Hello JavaScript!" into an HTML element with id="demo":

Example

<script>
document.getElementById("demo").innerHTML = "Hello JavaScript!";
</script>

A Taste of JavaScript

Here are some examples of what JavaScript can do:

JavaScript can change HTML content

 

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