Introduction to JavaScript

JavaScript is the web’s programming language. To add dynamic features to a web page or to provide interactivity, JavaScript is used. Most web pages use JavaScript to perform some basic tasks – for example, redirecting the user to another page, storing information about the user or displaying dynamic menus.

JavaScript is a very mature language. It first appeared in 1995, and all major web browsers have supported it for many years. While there is no standard JavaScript implementation that defines what exactly should happen when a particular piece of code is run, the JavaScript reference hosted at Mozilla.org is accepted as the standard documentation for JavaScript.

JavaScript is easy to learn, but it's still very powerful. JavaScript is what is called a scripting language, in that you, as the developer, write JavaScript instructions that the web browser will then interpret and execute on the fly.

So, what can JavaScript do?

Well, if you've ever seen something interesting things happen to a web page without you loading a new page, chances are JavaScript made it happen. These are just some of the things JavaScript can be used for:

• Clocks and timers / count-downs
• Animating page elements
• Validating form input
• Tracking a user browsing your site

As JavaScript has been in use for several years, there are many freely available JavaScript scripts that you can easily use and customize for your website.