C++ fstream Reads and writes several objects to disk

#include <fstream>
#include <iostream>
using namespace std;
class person                      //class of persons
{
   protected:/*ww  w  .  jav a 2 s .  c o  m*/
   char name[80];              //person's name
   int age;                    //person's age
   public:
   void getData()              //get person's data
   {
      cout << "\n   Enter name: "; cin >> name;
      cout << "   Enter age: "; cin >> age;
   }
   void showData()             //display person's data
   {
      cout << "\n   Name: " << name;
      cout << "\n   Age: " << age;
   }
};
int main()
{
   char ch;
   person pers;                   //create person object
   fstream file;                  //create input/output file
   //open for append
   file.open("GROUP.DAT", ios::app | ios::out |
   ios::in | ios::binary );
   do                             //data from user to file
   {
      cout << "\nEnter person's data:";
      pers.getData();             //get one person's data
      //write to file
      file.write( reinterpret_cast<char*>(&pers), sizeof(pers) );
      cout << "Enter another person (y/n)? ";
      cin >> ch;
   }
   while(ch=='y');                //quit on 'n'
      file.seekg(0);                 //reset to start of file
   //read first person
   file.read( reinterpret_cast<char*>(&pers), sizeof(pers) );
   while( !file.eof() )           //quit on EOF
   {
      cout << "\nPerson:";        //display person
      pers.showData();            //read another person
      file.read( reinterpret_cast<char*>(&pers), sizeof(pers) );
   }
   cout << endl;
   return 0;
}