closure syntax: (function a(){})() == (function a(){}())?

Question

I've noticed that Google Closure Compiler seems to use both interchangeably.

1.

(function a() {
  window.requestAnimationFrame(function() {
    //
    a();
  });
})();

2.

(function a() {
  window.requestAnimationFrame(function() {
    //
    a();
  });
}());

No problem. Searching for punctuation marks is quite difficult. — Kijewski, Apr 04 '13 at 18:46
@Kay I was looking for that too. May I ask how you found it? — bfavaretto, Apr 04 '13 at 18:46
Thanks, I tried similar searches but couldn't find it... @Kay — bfavaretto, Apr 04 '13 at 18:49
Here is another one: http://stackoverflow.com/questions/939386/immediate-function-invocation-syntax — bfavaretto, Apr 04 '13 at 18:49

score 1 · Answer 1 · answered Apr 04 '13 at 18:39

There is no one "closure syntax" : any syntax ensuring you build a function expression, that is a function expression that the compiler can't confuse with the start of a function definition, and you call it is OK. Here, both work.

You could for example have used

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

Simply choose the one that is the most readable and the less surprising. I think the first one, in which the call parenthesis are the most visible, is the most used and expected.

closure syntax: (function a(){})() == (function a(){}())?

1 Answers1