Avascript anonymous function application Example _javascript tips

Source: Internet
Author: User

Self-executing anonymous functions in JavaScript
Format:

(function () { 
//code 

Explanation: This is quite elegant code (if you first see a possible confused:), the first pair of parentheses of the enclosing function (function () {}) returns an unnamed function to the script, followed by a pair of empty parentheses that immediately executes the returned unnamed function, with the parameters of the anonymous function in parentheses.
Here's an example with a parameter:

(function (ARG) { 
alert (arg+100); 
}) (20); 

Important use: You can use it to create namespaces, as long as you write all of your code in this particular function package, then the outside can not access, unless you allow

(function () { 
function $ (ID) {return 
document.getElementById (ID); 
} 
function __addclass (id,classname,classvalue) { 
$ (id). style.classname=classvalue; 
} 
window[' MySpace ']={}; 
window[' mySpace ' [' addclass ']=__addclass; 
}] ();

The above example allows you to encapsulate and protect all of your functions, objects, and variables with this pseudo namespace. Also, because they are in the same function, they can be referenced to each other. In order to be global to the protected Code, a subsequent pair of parentheses tells the browser to execute the returned anonymous function immediately, and the __addclass () is assigned to a method of window during execution, so that only addclass can be performed externally and __addclass is protected. I can call it this way: Myspace.addclass (' Oneid ', ' font-width ', ' bold ')

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.