//DISPLAY 11.1 Equality Function
//Program to demonstrate the function equal. The class DayOfYear
//is the same as in Self-Test Exercise 23-24 in Chapter 6.
#include <iostream>
using namespace std;

class DayOfYear
{
public:
    DayOfYear(int theMonth, int theDay);
    //Precondition: theMonth and theDay form a
    //possible date. Initializes the date according
    //to the arguments.

    DayOfYear( );
    //Initializes the date to January first.

    void input( );

    void output( );

    int getMonth( );
    //Returns the month, 1 for January, 2 for February, etc.

    int getDay( );
    //Returns the day of the month.
private:
    void checkDate( );
    int month;
    int day;
};

bool equal(DayOfYear date1, DayOfYear date2);
//Precondition: date1 and date2 have values.
//Returns true if date1 and date2 represent the same date;
//otherwise, returns false.

int main( )
{
    DayOfYear today, bachBirthday(3, 21);

    cout << "Enter today's date:\n";
    today.input( );
    cout << "Today's date is ";
    today.output( );

    cout << "J. S. Bach's birthday is ";
    bachBirthday.output( );


	if ( equal(today, bachBirthday))
        cout << "Happy Birthday Johann Sebastian!\n";
    else
        cout << "Happy Unbirthday Johann Sebastian!\n";
    return 0;
}

bool equal(DayOfYear date1, DayOfYear date2)
{
     return ( date1.getMonth( ) == date2.getMonth( ) &&
                date1.getDay( ) == date2.getDay( ) );
}

DayOfYear::DayOfYear(int theMonth, int theDay)
                  : month(theMonth), day(theDay)
{
    checkDate();
}

int DayOfYear::getMonth( )
{
    return month;
}

int DayOfYear::getDay( )
{
    return day;
}

//Uses iostream:
void DayOfYear::input( )
{
    cout << "Enter the month as a number: ";
    cin >> month;
    cout << "Enter the day of the month: ";
    cin >> day;
}

//Uses iostream:
void DayOfYear::output( )
{
    cout << "month = " << month
         << ", day = " << day << endl;
}