How can I convert a comma-separated string to an array?

Question

I have a comma-separated string that I want to convert into an array, so I can loop through it.

Is there anything built-in to do this?

For example, I have this

Answer 1

Note that the following:

var a = "";
var x = new Array();
x = a.split(",");
alert(x.length);

will alert 1