switch确定某天是该年第几天

  Scanner str = new Scanner(System.in);

  System.out.print("请输入年份：");

  int Year = str.nextInt();

  System.out.print("请输入月份：");

  int Month = str.nextInt();

  System.out.print("请输入天：");

  int Day = str.nextInt();

   switch (Month－1) {

   case 11:Day＋=30；;

   case 10:Day += 31;

   case 9:Day += 30;

   case 8:Day += 31;

   case 7:Day += 31;

   case 6:Day += 30;

   case 5:Day += 31;

   case 4:Day += 30;

   case 3:Day += 31;

   case 2:Day += （Year%4=＝0&&Year%100!=0||Year%400=＝0）?29:28;

   case 1:Day += 31;

   case 0:break;

   default:System.out.print("输入有误！");

}

System.out.print("该天是当年的第" + Day + "天");