How does JavaScript work on the web

JavaScript course - learning JavaScript for beginners

JavaScript has boomed in recent years. Not least because of the massive use of AJAX, in which JavaScript is a large part (the J in AJAX stands for JavaScript).

What is JavaScript?

JavaScript is a programming language introduced by Netscape. Therefore, the Netscape browser could usually do a little more than Microsoft's in this area. And here, too, lies the great danger. There are small but subtle differences - otherwise the built-in JavaScript program only works for some surfers.

So JavaScript is a programming language that runs in the browser and is therefore client-side. Content on a website can be changed via JavaScript and displayed differently depending on the setting or visitor action. Just look at forms that react immediately to missing or incorrect user input. JavaScript is an important part of AJAX - therefore the basics are laid here step by step and the basics in JavaScript are shown before AJAX.

What do you need to program JavaScript?

Like HTML, JavaScript can be read in plain text. It can either be included directly in the HTML page or swapped out as a separate file. We'll get to outsourcing later.

Apart from an internet browser and a text editor, we don't need anything else. The interpreter for JavaScript is integrated in the internet browser (if not deactivated there). JavaScript does not have to be installed separately.

Firefox is the first choice as a browser, as it makes learning JavaScript much easier with additional tools and tools that are already integrated. In the past, the first thing to do was to install the “Firebug” plug-in in Firefox (download from - nowadays, the Firefox Developer Edition already has the appropriate tools integrated.

This can be used for debugging and testing. You can also go through the DOM. More on that later.

Structure of the JavaScript tutorial

At the end of the JavaScript course, everyone should be able to integrate finished JavaScript code into their own website. There are already numerous of these ready-made JavaScript programs. In the next step, the interaction of JavaScript and AJAX is examined and then the most widely used JavaScript library jQuery.

Now let's take a look at the structure, implementation and possibilities of JavaScript.