```java
package Chapter2;
import java. util. Scanner;
public class ShowDays {
public static void main(String[ ] args) {
System. out. println("请输入年份:");
Scanner inYear = new Scanner(System. in);
int year = inYear. nextInt( ); //输入年
System. out. println("请输入月份:");
Scanner inMonth = new Scanner(System. in);
int month = inMonth. nextInt( ); //输入月份
int numDays = 0;
switch(month) { //以月份作为分支条件
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:numnDays = 31; //1、3、5、7、8、10、12月天数为31
break; //跳出swith语句
case 4:
case 6:
case 9:
case 11: numDays = 30; //4、6、9、11月天数为30
break;
case 2: //对于2月，根据是否为闰年判断当月天数
if(((year % 4 ==0) && !(year % 100 == 0)) ||(year % 400==0)) |numDays 29;
} else {
numDays =28;
}
break;
}
System. out. println(year+"年"+month+"月份"+" 有"+numDays+" 天");
}
}```
*java语言程序设计（湖南大学出版社）案例2-8
