jQuery / Javascript - How do I convert a pixel value (20px) to a number value (20)

Question

I know jQuery has a helper method for parsing unit strings into numbers. What is the jQuery method to do this?

var a = "20px";
var b = 20;
var c = $.parseMethod(a) + b;

Answer 1

 var c = parseInt(a,10);

Answer 2

No jQuery required for this, Plain Ol' JS (tm) will do ya,

parseInt(a, 10);

Answer 3

$.parseMethod = function (s)
{
    return Number(s.replace(/px$/, ''));
};

although how is this related to jQuery, I don't know