JavaScript self-executing functions (immediately-invoked function Expression)

Source: Internet
Author: User

1. The JavaScript compiler, when encountering the keyword "function", is considered by default to be a function declaration, not an expression.

2. You can call it after the declared function is enclosed by parentheses. Like what

function foo () {console.log (' Hello JavaScript. ')}

Foo ();

3. The parentheses allow the JavaScript expression, (function () {Console.log (' Hello JavaScript ')}) so that the anonymous function is an expression, not a function declaration. Based on the 2nd above, the parentheses are followed to execute the function, i.e. (function () {Console.log (' Hello JavaScript ')}). This notation is equivalent to (function () {Console.log (' Hello JavaScript ')} ()), which is recommended.

The following methods are equivalent without regard to the return value

+function () {console.log (' Hello JavaScript ')} ()

-function () {console.log (' Hello JavaScript ')} ()

!function () {console.log (' Hello JavaScript ')} ()

~function () {console.log (' Hello JavaScript ')} ()

New function () {Console.log (' Hello JavaScript ')}

New function (name) {Console.log (' hello JavaScript ' + name;)} (' Bruce ')

JavaScript self-executing functions (immediately-invoked function Expression)

Related Article

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: 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.