Classes and objects

The source code for program that can check if a numbers prime is given below, copy it in note pad and save it as “.cpp”. Then use suitable compiler to compile it.

        /*
         *      
         *      Copyright 2011 techstream.org < techstream.org[at]gmail.com >
         *      
         *      This program is free software; you can redistribute it and/or modify
         *      it under the terms of the GNU General Public License as published by
         *      the Free Software Foundation; either version 2 of the License, or
         *      (at your option) any later version.
         *      
         *      This program is distributed in the hope that it will be useful,
         *      but WITHOUT ANY WARRANTY; without even the implied warranty of
         *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
         *      GNU General Public License for more details.
         *      
         */
        
        #include
        #include      // to use clrscr and getch
        class stud {
                int rno;
                float mark[5],total,percent;
                char name[20];
                void calcpercent()
                {
                   percent=(total*100)/500;
                }
               public:
                void getdata();
                void output();
               };
               void stud::getdata()
               {
               
                total=0;
                clrscr();
                cout<<"enter roll no: ";
                cin>>rno;
                cout<<"enter name: ";
                cin>>name;
                cout<<"enter marks:n ";
                for(int i=0;i<5;i++)
                 {
                    cout<<"enter mark in subject"<>mark[i];
                    total=total+mark[i];
                 }
                     calcpercent();
                  }
                  void stud::output()
                  {
                    clrscr();
                cout<<"n roll number :"<