Javascript Explained: What Does It Do?

Javascript is all about making web design more dynamic; whilst HTML and CSS have classically focused on laying out the page and content for you to look at, javascript made it possible to start adding in things you could interact with, it made web pages a living thing rather than a static display and integrated cleanly and easily into HTML pages.

Some people call it a toy code which just generates silly little widgets like a current time display, and early on this was how it got marketed to people. Web designers who knew HTML but didn’t want to learn anything else could pick up pre-written javascript code to create all kinds of little gimmicks on websites, however over time it has shown itself to be extremely useful and seamless to integrate with HTML, Flash and many other languages. This has led to its place as one of the most commonly used web design and programming languages on the web.

Some classic examples of Javascript usage include;

• Simple animation of page elements such as fading a picture in and out or drop down and sliding website menus
• Responding to clicks or mouseovers, such as changing the background image on click, zooming a picture on mouseover or creating a lightbox effect on picture galleries
• Making it possible for all kinds of simple games, music and video to be played on a webpage instead of forcing you to download the files and play them on your PC software; things like Pac-Man, Minesweeper and chess are all available as javascript games
• Gathering data; Google analytics, an add on to web designs to provide detailed traffic stats, runs largely on javascript, gathering data from your website and presenting it in your Google account, whilst Facebook website plug ins provide two way data presenting bits of Facebook on your site and gathering info on how people on your site interact with the plug in
• Sign up forms and website log ins, including auto-complete functions
• Updating of parts of a web design without refreshing the page, such as live sports results or stock market tickers

Javascript gets used in numerous other ways as well, such as within PDFs or numerous desktop widgets, its ability to respond to things in real time is one of its greatest uses and most often exploited features.

Many other programming languages have grown out of javascript or acted as add-ons to it, expanding what the basic language was capable of over time. Processing.js expands on graphics capabilities, CoffeeScript makes it more concise, Quby links javascript and Ruby to enable game playing, Phype links javascript and PHP, while Ajax links it with XML. From an early image issue as a gimmicky toy, javascript has grown to become the glue which binds a very expansive range of programming languages and technologies together in website design.