How to get just numeric part of CSS property with jQuery?

Question

I need to do a numeric calculation based on CSS properties. However, when I use this to get info:

$(this).css(\'marginBottom\')

it returns

Answer 1

This will clean up all non-digits, non-dots, and not-minus-sign from the string:

$(this).css('marginBottom').replace(/[^-\d\.]/g, '');

UPDATED for negative values