Write A C++ Program How: Structures And Classes Are Related.

#include <iostream.h> 
 #include <string.h> 
 #include<conio.h> 
 struct str 
 { 
     void dstr(char *s); 
     void showstr(); 
     private: 
                   char str [255]; 
 }; 
                   void str::dstr(char *s) 
                     { 
                         if(!*s)*str ='\0'; 
                         else strcat(str,s); 
                      } 
                          void str::showstr() 
                            { 
                                    cout<<str<<"\n"; 
                             } 
             void main() 
          { 
               clrscr(); 
               str s; 
               s.dstr(""); 
               s.dstr("Hello") ; 
               s.dstr("there!"); 
               s.showstr(); 
               getch(); 
          }