SQL with Manoj

Q16. Program to implement Operator Overloading with Unary Operators (++, –):

Define a DATE class with month, day & year as the private data member.
Implement Operator Overloading for finding the next day of given date.

… from College notes (BCA/MCA assignments):

#include <iostream.h>
#include <conio.h>

class CDATE{
	private:
		int dd, mm, yy;
		int _days;
		static int months[12];
	public:
		void Init(){
			cout<<"\n Enter a Date (dd mm yyyy): ";
			cin>>dd>>mm>>yy;
			}
		void operator++(){
			_days = DaysThisMonth(mm, yy);
			if(dd >=_days){
				if(mm >= 12){
					yy += 1;
					mm = 1;
					}
				else
					mm += 1;
				dd = 1;
				}
			else
				dd += 1;
			cout<<"\n Next Date: "<<dd<<":"<<mm<<":"<<yy;
			}
		int DaysThisMonth(int, int);
	};

int CDATE :: months[12] = { 31, 29, 31, 30, 31, 30,
					 31, 31, 30, 31, 30, 31 };

int CDATE :: DaysThisMonth(int mm, int yy){
	if (mm != 2)
		return months[mm-1];

	if (yy % 4)       // Not leap year
		return 28;
	if (yy % 100)     // It is leap year
		return 29;
	if (yy % 400)     // Not leap year
		return 28;
	return 29;          // It is leap year
	}
void main(){
	CDATE dt;
	clrscr();
	dt.Init();
	char ch;
	while(ch != 'y'){
		++dt;
		cout<<"\t\t\t Quit (y/n) ?: ";
		cin>>ch;
		}
	cout<<"\n\n Press Any Key to Exit ...";
	getch();
	}

Output:

Enter a Date (dd mm yyyy): 26 12 2003

Next Date: 27:12:2003 Quit (y/n) ?: n

Next Date: 28:12:2003 Quit (y/n) ?: n

Next Date: 29:12:2003 Quit (y/n) ?: n

Next Date: 30:12:2003 Quit (y/n) ?: n

Next Date: 31:12:2003 Quit (y/n) ?: n

Next Date: 1:1:2004 Quit (y/n) ?: n

Next Date: 2:1:2004 Quit (y/n) ?: n

Next Date: 3:1:2004 Quit (y/n) ?: n

Next Date: 4:1:2004 Quit (y/n) ?: n

Next Date: 5:1:2004 Quit (y/n) ?: y

Press Any Key to Exit …