目的- c:类方法vs实例方法-效率差异?

For the sake of tidiness and reusability, I'm thinking about putting a bunch of utility methods inside a single class. The class does not require any properties of its own and so I will define the methods as class methods; I figure that's there's no real need to have an instance of this class floating around…For the sake of tidiness and reusability, I'm t