What's the technique that the Google analytics tracking code uses?

Question

The Google Analytics tracking code looks like this:

(function() {
code
  })();

What\'s the technique they are using with those brackets -

Answer 1

It's just a select calling function. The () at the end causes it to be called automatically.

It's used like this to isolate local variables that are relevant only to your code from the global scope.

For example:

(function() {

   var x = 5;
   window.y = 6;

})();

x is available only in the scope of the function, y is globally available through the window.

As to it not running, I'd hazard that's down to the conditional you supplied.