Static Member Functions of Class in C++

Like static member variable, we can also have static member functions in a class. A member function that is declared static has the following properties:

1. A static member function can have access to only other static members (functions or variables) declared in the same class
2. A static member function can be called using the class name (instead of its objects) as follows:
   
   1	class-name :: function-name;

Program below illustrates the implementation of these characteristics:

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#include <iostream.h> class test      {           private:                int code;                static int count;     //static member variable           public:                void setcode()                     {                          code = ++count;                     }                void showcode()                     {                          cout << "Object number: " << code << endl;                     }                static void showcount()     //static member function                     {                          cout << "Count: " << count << endl;                     }      };        int test :: count;        void main()           {                test t1, t2;                  t1.setcode();                t2.setcode();                  test :: showcount();     //accessing static function                  test t3;                t3.setcode();                  test :: showcount();     //accessing static function                  t1.showcode();                t2.showcode();                t3.showcode();      }

Output of the above program would be:

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count: 2 count: 3 Object number: 1 Object number: 2 Object number: 3

In the above program:

1. The static member function showcount() displays the number of objects created till that moment
2. A count of number of objects created is maintained by the static variable count
3. The function showcode() displays the code number of each object
4. Note that the statement:
   code=++count;
   is executed whenever setcode() function is invoked and current value of count is assigned to code. Since each object has its own copy of code, the value contained in code represents a unique number of its object