out break void pri sta cas || 編程 pub

輸入某年某月某日，判斷這一天是這一年的第幾天？

public class Example14 {
public static void main(String[] args) {
year(2017, 1, 1);
}

public static void year(int year, int month, int day) {
int d = 0;
int days = 0;
if (year < 0 || month < 0 || month > 12 || day < 0 || day > 31) {

System.out.println("輸入錯誤，請重新輸入！");
}
for (int i = 1; i < month; i++) {
switch (i) {
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
days = 31;
break;
case 4:
case 6:
case 9:
case 11:
days = 30;
break;
case 2:
if ((year % 400 == 0) || (year % 4 == 0 && year % 100 != 0)) {
days = 29;
} else {
days = 28;
}
break;
}
d += days;
}
System.out.println(year + "年" + month + "月" + day + "日是" + year + "的第"
+ (d + day) + "天。");
}
}

Java經典編程題50道之十四