JS - (function(){} ()) What does it do?

Asked Aug 27 '14 at 11:14

Active Aug 27 '14 at 11:17

Viewed 47 times

I am trying something and I saw Facebook SDK's code:

(function(d, s, id) {
    var js, fjs = d.getElementsByTagName(s)[0];
    if (d.getElementById(id)) return;
    js = d.createElement(s); js.id = id;
    js.src = "//connect.facebook.net/en_US/sdk.js";
    fjs.parentNode.insertBefore(js, fjs);
}(document, 'script', 'facebook-jssdk'));

Can someone explain to me what does (function(){}()) do? I can't Google it since brackets are consider a syntax on Google.

asked Aug 27 '14 at 11:14

Daniel Cheung

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It's an IIFE, it will be called just after creation. – Mritunjay Aug 27 '14 at 11:15
also [Why do you need to invoke an anonymous function on the same line](http://stackoverflow.com/questions/1140089/why-do-you-need-to-invoke-an-anonymous-function-on-the-same-line) – Yuliam Chandra Aug 27 '14 at 11:18
1

"I can't Google it" - [try SymbolHound](http://symbolhound.com/?q=%28function%28%29{}%29%28%29)! – MarioDS Aug 27 '14 at 11:20
@MDeSchaepmeester Wow! Never heard of that! Thank you, I learnt a new thing. – Daniel Cheung Aug 27 '14 at 11:49
@YuliamChandra, but the last bracket is inside, does that matter? – Daniel Cheung Aug 27 '14 at 11:51
@DanielCheung, same thing different combination – Yuliam Chandra Aug 27 '14 at 12:35

JS - (function(){} ()) What does it do?

0 Answers0