Days.java

// Days.java -- A Java program illustrating "case"

class Days  {

   private static final int DEFAULT_YEAR = 2021;

   public static void main (final String[] args)  {

      final int month = Integer.parseInt (args[0]);
      final int year = args.length>1?Integer.parseInt (args[1]):DEFAULT_YEAR;

      final int numDays;    // Blank final declaration

      switch (month) {
      case 1:
      case 3:
      case 5:
      case 7:
      case 8:
      case 10:
      case 12:
         numDays = 31;
         break;

      case 4:
      case 6:
      case 9:
      case 11:
         numDays = 30;
         break;

      case 2:
         if (((year%4==0) && !(year%100==0)) || (year%400==0)) {
            numDays = 29;
         } else {
            numDays = 28;
         }
         break;

      default:
         numDays = 0;
         break;
      }

      System.out.printf ("Number of days = %d%n", num_days);
   }
}