JavaScript and DHTML Pages
JavaScript Overview
JavaScript (JS) has been around in one form of the other almost as long as webpages have and is an extremely useful way to add simple client-side applications.
However JS has also evolved along with mainstream web-development and has acquired functionality to change the CSS properties of the document or any element within it up to and including the displayed content. This gives rise to some very interesting client-side interactions, giving this technique its name; Dynamic HTML - DHTML.
JavaScript + CSS = DHTML
JavaScript coding is yet another vast subject, once again there are »plenty of websites out there dedicated to this subject so we
won't go into it any more than necessary.
Here the focus is on how the JS is used, its application. It is assumed
that you are at least moderately familar with the language and programming
in general, if you aren't then you are strongly advised to brush up on these
first.
Here we consider how JS can be utilised within webpages and there are a number of examples of simple JS/DHTML methods that can add a great deal of useful functionality to a page. There are also a number of complete utilities or puzzle games, something which would be almost impossible as a client-side application without DHTML.
The boundary between JS and DHTML is hard to define, on a modern website the two are often inseparable. Indeed DHTML is invariably coded in JS, and nowadays JS exists primarily to support DHTML.
Finally, JS is very accessible, even static .html files browsed through your filesystem will support it thus giving a readily available programing environment for any would be programmers out there to cut their teeth on. As a scripted language it uses a simple syntax common to many other languages, if you are already familiar with Perl or C family languages you will have little trouble with JS.