Prevent 'global' references in javascript

Question

I've got a problem of having code variable names conflicting each other, ie;

<script type="text/javascript">var a = "hello"; </script>
<script type="text/javascript">alert(a);//this works, when I want 'a' not to exist </script>

Are closures the only option?

Coming from a c# background, its like constructing an unreferenced instance of a delegate, then calling it inline, which seems a bit messy

(function(){var a = "hello";})();
(function(){alert(a);})();//yes! working as expected

Answer 1

Using a (immediately self-executing) function to create a new scope is indeed the way to go.

This also has the advantage that you can ensure that certain variables have certain values. When using jQuery, the following is common for example:

(function($, window, undefined) {
    // ...
})(jQuery, this);

Unless you have tons of functions with only a single statement in each (like in your example) it is also perfectly readable.