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JavaScript

Posted by The Machine
The Machine
10,221 Points

Is there a difference between '+' and '!' for JavaScript self-calling anonymous function modular pattern?

(from Track "The Module Pattern in JavaScript")

4 Answers

Ryan Zimmerman
Ryan Zimmerman
3,854 Points
Ryan Zimmerman
Ryan Zimmerman
3,854 Points

Hi Brac,

Can you give more context?

The Machine
The Machine
10,221 Points

Regarding wrapping all code in a single JavaScript file with a self-executing anonymous function, i.e.

;(function(){
    // ...code...
}());

In multiple files, so ; is needed at beginning as well so that file inclusion is not order dependent. Can simplify to:

+function(){
    // ...code...
}();

OR

!function(){
    // ...code...
}();

Reference first 5 minutes of: https://teamtreehouse.com/library/the-module-pattern-in-javascript-2

My question is -- is there a functional difference between using the + and !, or is it just personal preference?

Thanks, Brac

Ryan Zimmerman
Ryan Zimmerman
3,854 Points
Ryan Zimmerman
Ryan Zimmerman
3,854 Points

Yeah, my answer would be no.

Best practice is to ;

Between that, module.exports and great server side bundlers you shouldn't have a problem.

The Machine
The Machine
10,221 Points

Thanks for the reply Ryan. To clarify -- you state there is no functionality difference between the three code examples above AND you would suggest sticking with the first, more verbose code example?

Ryan Zimmerman
Ryan Zimmerman
3,854 Points
Ryan Zimmerman
Ryan Zimmerman
3,854 Points

Yes

Ryan Zimmerman
Ryan Zimmerman
3,854 Points
Ryan Zimmerman
Ryan Zimmerman
3,854 Points

http://underscorejs.org/docs/underscore.html

The Machine
The Machine
10,221 Points

Thanks Ryan!