/**
 * @(#)FinalExamJG.java
 *
 * FinalExamJG application
 *
 * @author
 * @version 1.00 2019/6/11
 */

public class FinalExamJG {
	int finalExamIDNum;
	int month;
	boolean Leap;
	int day;
	int year;

	public FinalExamJG(int IDNum, int mon, int d, int y) {
		// Assigns ID num
		if (IDNum < 2000)
			finalExamIDNum = 22;
		else
			finalExamIDNum = IDNum;

		// Assigns month
		if ((mon < 1) || (mon > 12)) {                // resets month if invalid along with day
			mon = 0;
			day = 0;
		} else
			month = mon;
		// Assigns Day
		if ((d < 1) || (d > 31))
			day = 0;
		else
			day = d;

		// assigns year
		if ((y < 2011) || (y > 2019))
			year = 0;
		else
			year = y;

		// Calculates when it's a leap year
		if (year % 4 == 0) {
			Leap = true;
 		/*	if (month == 2) {				//Old leap year february code
 				if (day > 29) {
 					day = 29;
 				}
 			}
    	}*/
		} else {                                // New leap year code
			Leap = false;
		}
		switch (month) {
			case 1:
				if (day > 31)                // Limit days per month
					day = 31;
				break;
			case 2:
				if (Leap == true) {
					if (day > 29)
						day = 29;
				} else if (day > 28) {
					day = 28;
				}                                    // completed leap year code
				break;
			case 3:
				if (day > 31)
					day = 31;
				break;
			case 4:
				if (day > 30)
					day = 30;
				break;
			case 5:
				if (day > 31)
					day = 31;
				break;
			case 6:
				if (day > 30)
					day = 30;
				break;
			case 7:
				if (day > 31)
					day = 31;

				break;
			case 8:
				if (day > 31)
					day = 31;
				break;
			case 9:
				if (day > 30)
					day = 30;
				break;
			case 10:
				if (day > 31)
					day = 31;
				break;
			case 11:
				if (day > 30)
					day = 30;
				break;
			case 12:
				if (day > 31)
					day = 31;
				break;
			default:
				System.out.println("Invalid month, Restart & try again");
		}
	}
}
==============================================================
public class TestFinalExamJG {
    public static void main(String[] args) {
        FinalExamJG t1 = new FinalExamJG(1999,2,29,2016); // Proves Leap year gets detected, IDNum
        FinalExamJG t2 = new FinalExamJG(2001, 2, 29,2019); // Further proves leap year, IDNum
        FinalExamJG t3 = new FinalExamJG(2001, 3, 32, 2021); // Day and year resets to 0
        FinalExamJG t4 = new FinalExamJG(2001, 13, 12, 2019); // Month cap resets to 0

        System.out.println(t1.finalExamIDNum + " " + t1.month + " " + t1.day + " " + t1.year);
        System.out.println(t2.finalExamIDNum + " " + t2.month + " " + t2.day + " " + t2.year);
        System.out.println(t3.finalExamIDNum + " " + t3.month + " " + t3.day + " " + t3.year);
        System.out.println(t4.finalExamIDNum + " " + t4.month + " " + t4.day + " " + t4.year);
    }
}