//DISPLAY 10.4 Class with Private Members //Program to demonstrate the class DayOfYear.#include <iostream>using namespace std;class DayOfYear{public: void input( ); void output( ); void set(int new_month, int new_day); //Precondition: new_month and new_day form a possible date. //Postcondition: The date is reset according to the arguments. int get_month( ); //Returns the month, 1 for January, 2 for February, etc. int get_day( ); //Returns the day of the month.private: void check_date( ); int month; int day;};int main( ){ DayOfYear today, bach_birthday; cout << "Enter today's date:\n"; today.input( ); cout << "Today's date is "; today.output( ); bach_birthday.set(3, 21); cout << "J. S. Bach's birthday is "; bach_birthday.output( ); if ( today.get_month( ) = = bach_birthday.get_month( ) && today.get_day( ) = = bach_birthday.get_day( ) ) cout << "Happy Birthday Johann Sebastian!\n"; else cout << "Happy Unbirthday Johann Sebastian!\n"; return 0;}//Uses iostream:void DayOfYear::input( ){ cout << "Enter the month as a number: ";cin >> month; cout << "Enter the day of the month: "; cin >> day; check_date( );}void DayOfYear::output( ) //The rest of the definition of DayOfYear::output is given in Display 10.3.>void DayOfYear::set(int new_month, int new_day){ month = new_month; day = new_day; check_date();}void DayOfYear::check_date( ){ if ((month < 1) || (month > 12) || (day < 1) || (day > 31)) { cout << "Illegal date. Aborting program.\n"; exit(1); }}int DayOfYear::get_month( ){ return month;}int DayOfYear::get_day( ){ return day;}