C ++, these three types of relationships are as follows:
We must first understand: static member function can call non-static data members, specifically how to call, see below.
class A
{
public:
static void fun ( A a )
{
cout << b <<endl;(错误)
cout << a.b<<endl;（正确）
}
privte:
int b;
}
As in the example above, if the static member function to call non-static data member, you must be using an object specific call, why?
The reason: Because static member functions and non-static data members are owned for the entire class, not specific to an object-specific, to call the static member function it is not the purpose of the object, unlike non-static member function as there is a we know this is like implicit objects of this class to access non-static members. So static member function parameter must be a way to access an object of a specific non-static data members.
to sum up:
(1) static member function can directly call the static data members and non-static member functions of the class, but call non-static data members when necessary to call the object parameter passed by the way.
(2) In general, (1) is also not recommended to call this non-static data members, the main role is to access static member function static data members of a class, the maintenance of data sharing between objects.
