What are the advantages of JQuery ?
There are many advantages with JQuery. Some of them are :
. It has the ability to keep the code simple, readable, clear and reusable.
. It would eradicate the requirement for writing complex loops and DOM scripting library calls.
How can you select all elements in a page using jQuery?
To select all elements in a page, we can use all selectors, for that we need to use *(asterisk symbol).
$("*").css("border", "2px dotted red");
The above code will select all elements of the web page and apply border width as 2 pixel, style as dotted and color as red.
Thanks and Regards
What is jQuery?
It was released in January 2006 at BarCamp NYC by John Resig.
It is free, open source software Dual-licensed under the MIT License and the GNU General Public License. Microsoft has integrated jQuery officially into its IDE Visual Studio 2010 and jQuery intellisense is available in Visual Studio 2010 now.
It helps to
# Improve the performance of the application
# Develop most browser compatible web page
# Implement UI related critical functionality without writing hundreds of lines of codes
# Extensible – jQuery can be extended to implement customized behavior
Other advantages of jQuery are
# Simple and Cleaner code, no need to write several lines of codes to achieve complex functionality.
How to use jQuery?
To load local jQuery file
Ideally this markup is kept in under <head></head> tag of your web page, however you are free to keep anywhere you want.
Do I need to refer jQuery file both in Master page/base page/template page and content page?
No, master page/base page/ template page basically helps to create consistent layout for the page in the application. In case you have referred the jQuery file in master page/base page/ template page that cause rendering the file in the browser, you do not need to refer jQuery file the content page again.
In summary, there should not be more than one <script> tag with jQuery file reference in the source code of the rendered web page in the browser.
What is the difference between jQuery-x.x.x.js and jQuery.x.x.x-min.js
In terms of functionality, there is no difference between the jQuery-x.x.x.js and jQuery-x.x.x-min.js (also called minified version). However this can play a vital role in the performance of the web page.
How it affects the performance?
jQuery-1.4.4.js file size is 178 KB as against its minified version jQuery-1.4.4-min.js that is only 76.7 KB in size. So when your page loads in the client?s browser if you are not using minified version, it loads 178 KB file that takes more time to load than 76.7 KB.
Which version of jQuery file should be used?
In most of the recent releases so far, the core functionality of jQuery remains same however some more cool and better features are added. Ideally you should use the latest jQuery files available on the jQuery.com website. By doing this you ensure that your earlier functionality will still work and you can use new features available as part of the new release.
What is CDN?
CDN Stands for Content Distribution Network or also called Content Delivery Network is a group of computers placed at various points connected with network containing copies of data files to maximize bandwidth in accessing the data. In CDN a client access a copy of data nearer to the client location rather than all clients accessing
from the one particular server. This helps to achieve better performance of data retrieval by client.
There are two leading CDNs available that hosts jQuery files.
Microsoft - To load jQuery from Microsoft AJAX CDN
jQuery file can be loaded from Microsoft AJAX CDN. For more details, go to http://www.asp.net/ajaxlibrary/cdn.ashx. You will need to keep following tags in your page.
Google - To load jQuery from Google Libraries API
jQuery file can be loaded from Google CDN for more details, go to http://code.google.com/apis/libraries/devguide.html. You will need to keep following tag in your page.
Why to load jQuery file from CDN?
The possibility is that if more and more websites are using CDNs, the user might have already browsed some other web pages that is using CDNs jQuery file and that file may have into browser cache; so when user browse your page and you are also using CDNs file, the older cached version of jQuery file will be used. In this way your page will load faster as browser will not have to load the jQuery file for your page again.
1. Faster page load as jQuery file need not to be downloaded
2. Saves your bandwidth as jQuery file is not loaded from your server
3. Scalable - generally CDNs place these files on the servers located at different geographical locations of the world so that they load faster so irrespective of from where your user is browsing your page, your application runs well.
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