This is the Welcome page for Javascript in general and for jQuery in particular. Both the script language Javascript and its plug-in, jQuery, are briefly described. It lists several articles written on the subject.

Javascript is a light-weight, object-oriented, interpreted , dynamic client-side scripting language known mainly because it is hosted by web browsers and can help turn a dull static web page into an engaging, interactive, and intelligent experience. JavaScript can be used to manipulate the very markup in the documents in which it is contained and it works in all major browsers, such as Internet Explorer, Firefox, Chrome, Opera, and Safari.

Unlike Java, Javascript is not fully object oriented since it is possible to define functions and variables outside objects. It stands in the same class of OOP as C++ or Delphi. On the other hand, unlike C++ and Delphi, Javascript is not compiled into optimized processor code but interpreted within a virtual machine translator running inside each browser (V8 in Chrome, Rhino in Firefox and SquirrelFish in Opera). This forces browser developers to reach some compromises to achieve cross-browser compatibility.

Cross-browser compatibility is exactly the main reason why I have always hated using Javascript. Programming cross-browser can only be done through all sorts of "hacks". This is why, this part of the site does not deal much with Javascript but plenty with jQuery. It's a great cross-browser JavaScript framework.

Quick introduction to jQuery

jQuery came out in January 2006. Its formal definition is « an open source Javascript library that simplifies the interactions between an HTML document, or more precisely the Document Object Model, and Javascript. » In other words, jQuery makes DHTML easy. Specifically, jQuery simplifies HTML document traversing and manipulation, browser event handling, DOM animation and cross-browser Javascript development. It is an encapsulation of the DOM.

The jQuery syntax is designed for selecting HTML elements and perform some action on the them. It uses a combination of XPath and CSS selector syntax. Every jQuery operation starts with selecting one or more nodes from the DOM. The basic syntax is: $(selector).action()

• A dollar sign to define jQuery;
• A (selector) to "query (or find)" HTML elements; and
• A jQuery action() to be performed on the element(s)

This snippet show a very short jQuery program:

<script src="http://jquery.com/src/jquery-latest.js"></script>   
<script type="text/javascript">     
$(document).ready(function()
{       
  $("dd label").append(":");     
  });   
</script>

There are three principle categories of jQuery methods: those that manipulate all of the matched elements, those that return a value from the first matched object, and those that modify the selection itself.

Articles

For the time being, the following articles are available: