JavaScript Introduction

JavaScript is the world's most popular programming language and the programming language of the Web.

What is JavaScript?

JavaScript is a lightweight, interpreted, or just-in-time compiled programming language with first-class functions. It is well-known as the scripting language for Web pages, many non-browser environments also use it, such as Node.js, Apache CouchDB and Adobe Acrobat.

JavaScript can update and change both HTML and CSS, and it can calculate, manipulate and validate data.

JavaScript Demo - Try It!

Try testing JavaScript out in the editor. Click the JS tab to see the script.

Why Learn JavaScript?

JavaScript is one of the 3 languages all web developers must learn:

1. HTML to define the content of web pages
2. CSS to specify the layout of web pages
3. JavaScript to program the behavior of web pages