public class MyCalender { public void printDayOfMonth(int month) { if(month >= 1 && month <= 12) { switch(month) { case 1: case 3: case 5: case 7: case 8: case 10: case 12: System.out.println("31 days"); break; case 2: case 4: case 6: case 9: case 11: System.out.println("30 days"); break; default: break; } } else { System.err.println("it's wrong month"); } }
public static void main(String[] args) { new MyCalender().printDayOfMonth(3); } }