Class Composition Example

#include <iostream.h>
/******************************************************************
 File: class6.C
 Instantiate an appointment class object. Initialize it using
 a constructor.  Set an appointment and display the appointment.
 The appointment class is composed of a date object and a time
 object. 
******************************************************************/

class date {
     int day;
     int month;
     int year;
public:
     date();
     void set_date();
     void get_date();
};

class time {
     int hours;
     int mins;
public:
     time();
     void set_time();
     void get_time();
};

class appointment {
     date ddmmyy;
     time hhmm;
public:
     appointment();
     void set_appt();
     void get_appt();
};

date::date()
{
     cout << "Constructing date..." << endl;
     day   = 0;
     month = 0;
     year  = 0;
}

void date::set_date()
{
     cout << "Enter date in DD MM YYYY format: ";
     cin >> day >> month >> year;
}

void date::get_date()
{
     cout << "The date stored in this object is:" << endl;
     cout << "Day: " << day << endl;
     cout << "Month: " << month << endl;
     cout << "Year: " << year << endl;
}

time::time()
{
     cout << "Constructing time..." << endl;
     hours   = 0;
     mins = 0;
}

void time::set_time()
{
     cout << "Enter time in HH MM format: ";
     cin >> hours >> mins;
}

void time::get_time()
{
     cout << "The time stored in this object is:" << endl;
     cout << "Hours: " << hours << endl;
     cout << "Minutes: " << mins << endl;
}


appointment::appointment()
{
     cout << "Constructing appointment..." << endl;
}

void appointment::set_appt()
{
     ddmmyy.set_date();
     hhmm.set_time();
}

void appointment::get_appt()
{
     ddmmyy.get_date();
     hhmm.get_time();
}

int main()
{
     appointment today;

     today.get_appt();
     today.set_appt();
     today.get_appt();

     exit(0);
}

Output: 

Constructing date...
Constructing time...
Constructing appointment...
The date stored in this object is:
Day: 0
Month: 0
Year: 0
The time stored in this object is:
Hours: 0
Minutes: 0
Enter date in DD MM YYYY format: 16 4 1997
Enter time in HH MM format: 1 15
The date stored in this object is:
Day: 16
Month: 4
Year: 1997
The time stored in this object is:
Hours: 1
Minutes: 15