Const function

Declaring a function with the key word const ,it is specifies that the function is Read Only method,that dones not modify that object for which it is called.

Class Date

{

                   int month;

       public:

                   Date (int month,int date,int year);

                   int getMonth(int month);

                  int setMonth(int month) const;//const method

                

};

int Date::setMonth(int mon)

{

month=mon;

}

int main()

{

               Date currentDate(1,1,2011);

               const Date birthDate(21,1,1987);

               currentDate.setMonth(2);//right

               birthDate,setMonth(2);//Error

               return 1;

}