With jQuery, what is the point of encapsulating a function in round brackets?

Question

I see this in some HTML files that use jQuery, at the bottom:

(function() {
        setTimeout(function(){window.scrollTo(0,0);},0);
    })();

What does it mean to put the whole function in round brackets?

It's to make the function asynchronous so it scrolls smoother ? — adeneo, Mar 25 '14 at 12:13

score 2 · Accepted Answer · answered Mar 25 '14 at 12:11

The code you gave as example is a self-executing anonymous function.

You can read more about them here.

Relevant text from that article:

What’s useful here is that JavaScript has function level scoping. All variables and functions defined within the anonymous function aren’t available to the code outside of it, effectively using closure to seal itself from the outside world.

score 2 · Answer 2 · answered Mar 25 '14 at 12:14

2

(function() {})(); means it is self executing anonymous function. It get called immediately when java script get rendered. More details you can search it.

answered Mar 25 '14 at 12:14

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score -1 · Answer 3 · answered Mar 25 '14 at 12:28

-1

setTimeout is a function which accepts two parameters:

First parameter: A function

Second parameter: an integer value in milliseconds.

By calling the setTimeout function, the function from first parameter will be called/invoked after the amount of time specified in the second parameter.

answered Mar 25 '14 at 12:28

Sujan Shrestha

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He is asking about the part `(function() { ... })()`, not about `setTimeout` :) – Daniël Knippers Mar 25 '14 at 12:32
Oh yes, I get it. Sorry for misunderstanding. – Sujan Shrestha Mar 25 '14 at 12:37

With jQuery, what is the point of encapsulating a function in round brackets?

3 Answers3