[jQuery] Check if an element DOESN'T have a class

[kgosser]

Hey all,

I understand how hasClass() works, but I'm trying to figure out how to
use it to see if an element DOESN'T have a class. I want to check if
the class doesn't exist, and if not then I'll add it.

Do I use the older is() method?

Just looking for the best way. Thanks!