static member functions

[novice]

What is the purpose in life of static member function?
I read somewhere that they deal with the static variables in the class.
But can't we deal with static data members from within non-static member
functions?

Thank you

[Rinesh Kumar Agnihotri]

Hello,
See there can be some good uses that static functions can be put to.
One of them is to make a singleton class i.e a class which can produce only
one object and not more.
It goes like this:
Supposing that you wish the user of your class to make only one object of
your class you can make the constructor of your class private and then ask
the user to call a function which would be a static function and as you know
that a static func. can be called even before an object is made and hence
you can implement the logic of the function such that whenever called it
checks if one object has been made, if it is so then it produces an error
message or returns the same reference or whatever otherwise it creates an
object and returns the reference to it.

I hope this satisfies,
Rinesh.

[Danny Kalev]

novice wrote:
>
> What is the purpose in life of static member function?
> I read somewhere that they deal with the static variables in the class.
> But can't we deal with static data members from within non-static member
> functions?

static member functions have several uses. The most important one is the
ability to call them even if no object instance exists. Ordinary member
function, by contrast, must called on an object. If you don't have an
object, you can't invoke a nonstatic member function. This feature
enables static member function to access static data members of a class,
which as you may already know, exist even if there's no object of that
class. You can use ordinary members to access static members but
sometimes you need to access them before you have created the first
object, for example, in the case of a Singleton or in reference counting
classes.

Danny
>
> Thank you