Hello World Using JQuery

Lets Start with a Simple Example as usual always the "Hello World"..
   Ok, let get start to create a JQuery Hello World
1.Create a Simple HTML Page say MyfirstJqueryProgram.html like below and place it in the folder
where you have placed jquery-1.2.6.min.js file
<html>                                                   
<head>
<title>My First JQuery Program</title>
<script type="text/javascript" src="jquery-1.2.6.min.js"></script>       
<script type="text/javascript"> 
$(document).ready(function(){
$("#myprogram").html("This is my first Jquery Program saying Hello World");
});                                   
</script>                                                              
</head>                                                                
<body>                                                                 
Hi Welcome !!!
<div id="myprogram">
</div>
</body>                                                                
</html>

 Explanation:
 code Part 1 :  
 The Above piece of code tells the browser to load the JQuery library which is located in the Folder you have created

 Code Part 2:
 $(document).ready(function(){
 $("#myprogram").html("This is my first Jquery Program saying Hello World");
});

Here we are registering a ready event ie whenever the DOM is Ready
$() is a JQuery syntax called jQuery selector

Downloading and Installing Jquery

2. Downloading and Installing Jquery

2.1 Downloading Jquery:
In this section we will download and install jQuery for developing our demo application. 
you can download the latest version of jQuery from its official site http://jquery.com/
After Downloading Jquery Follow the Below Steps for Installing Jquery.

2.2     Installing Jquery
         jQuery comes as single js file. So, its very easy to download and install jQuery in any web application. You can even add it to your existing application and use jQuery functions. Due to this simplicity programmers are using jQuery for adding Ajax capabilities into their web applications.

 download jquery-1.2.6.min.js and add into js directory of your application. You can rename it to jquery-1.2.6.js.You are now all set and ready to add the jQuery support into your web application.In the next section we will show you how you can develop your first Ajax jQuery application that shows the current server time.

Introduction to jQuery-Part 1

1.1 About Jquery                                                                           
JQuery is a fast and concise JavaScript Library that simplifies HTML document traversing, event handling, animating, and Ajax interactions for rapid web development.
 jQuery is an exceptionally clever piece of engineering. It neatly encapsulates an extraordinary range of common functionality, and provides a clever plugin API for any functionality not included by default.
 Using JQuery makes the code light weight and executes faster at the client side. JQuery separates the "behavior" characteristics from the HTML structure

1.2 Why Jquery?
     Unlike most other JavaScript libraries, jQuery works in a different manner. What sets it apart is something known as “Chainablity”. This is somewhat related and like object oriented programming. For one, jQuery generated code is less heavier or smaller than prototypes. Unlike jQuery, which uses OO concepts, prototype – as a JavaScript library, only encourages them. Even if you have used other JavaScript libraries, I, as web developer would definitely suggest you guys at least trying out jQuery. Its simple, short and sweet  and Its powerful, light and fun!
Google, Yahoo, Dell, Bank Of America, also have adopted and used jQuery for developing and deploying their website or website based products

1.3 Where can you get jQuery and other JavaScript libraries?
     jQuery is free and is available at http://jquery.com/. Its small ~15kb and you can find a lot of tutorials and discussions too.

1.4 Features of Jquery
DOM element selections using the cross-browser open source selector engine
jQuery owns a strong and very flexible mechanism for adding in methods and functionality,bundled as plugins
CSS manipulation
Effects and animations
Ajax
Extensibility through plugins
Utilities - such as browser version and the each function.

1.5 jQuery Advantages
jQuery supports CSS 1-3 and basic XPath.
jQuery is about 19kb in size.
jQuery works in Firefox 1.0+, Internet Explorer 5.5+, Safari 1.3+, and Opera 8.5+.
jQuery and Prototype can be used together!