What is static function?

- Static member functions are used to maintain a single copy of a class member function across various objects of the 

class. Static member functions can be called either by itself, independent of any object, by using class name and :: 

(scope resolution operator) or in connection with an object.

- Restrictions on static member functions are :

1. They can directly refer to other static members of the class.

2. Static member functions do not have this pointer.

3. Static member function can not be virtual.

- Though there are several restrictions on static member functions, one good use of them is to initialize private static 

data members of a class before any object is created.

- Example :