Javascript objects/closures

Question

Can a JS guru out there explain why this:

$$={}
(function(x){
 x.newModule = {
 func: function(){...}
 };
})($$);
$$.newModule.func()

is superior to this?

$$.newModule = {
 func: function() {...}
}
$$.newModule.func()

• Danilo Valente: What do you mean with superior?

Answer 1

The extra function gives you an extra local scope that you might want to use (though it is not in your short example).

(function(x){
 var privateFunction = function() {};
 var privateCounter = 1;
 x.newModule = {
 func: function(){...}
 };
})($$);

• nnnnnn: Also, x only saves one character over $$, but a real-world example might have x and myNamespace.mySubNamespace.someObject so if you needed to reference the object repeatedly to add multiple methods and/or properties giving it a one-character alias makes the code neater and easier to read.
• Thilo: @nnnnnn: And the module author might be a different person than the module user, and with this "export"-like syntax, each gets to choose her own favorite names.

Answer 2

In the first pattern you can have private methods and variables which are not possible in the second pattern. That is the reason the first pattern is superior.