 void Distance::inputfeet0(double feet0) {     if(feet0 < 0)     {         cout<<"Cannot be less than zero. Default value of 0 is used.";     }     else     {         feet_0 = feet0;     } }//added this  void Distance::inputfeet0(double feet0) {     if(feet0 < 0)     {         cout<<"Cannot be less than zero. Default value of 0 is used.";     }     else     {         feet_0 = feet0;     } }//added this 