*3.11(Find the number of days in a month) Write a program that prompts the user to enter the month and year and displays the number of days in the month. For example, if the user entered month 2 and year 2012, the program should display that February 2012 had 29 days. If the user entered month 3 and year 2015, the program should display that March 2015 had 31 days.
（查找一个月的天数）编写一个程序，提示用户输入月份和年份，并显示这个月的天数。例如，如果用户输入了2012年2月，程序应该显示2012年2月有29天。如果用户输入了3个月和2015年，程序应该显示2015年3月有31天。
代码如下：
import java.util.Scanner;
public class test {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("请输入年份year");
int year = scan.nextInt();
System.out.println("请输入月份month");
int month = scan.nextInt();
int days=0;
if(year % 4==0)
{
switch(month)
{
case 1:
days=31;
break;
case 2:
days=28;
break;
case 3:
days=31;
break;
case 4:
days=30;
break;
case 5:
days=31;
break;
case 6:
days=30;
break;
case 7:
case 8:
days=31;
break;
case 9:
days=30;
break;
case 10:
days=31;
break;
case 11:
days=30;
break;
case 12:
days=31;
break;
}
System.out.println(year+"年"+month+"月有"+days+"天");
}
else
{
switch(month)
{
case 1:
days=31;
break;
case 2:
days=29;
break;
case 3:
days=31;
break;
case 4:
days=30;
break;
case 5:
days=31;
break;
case 6:
days=30;
break;
case 7:
case 8:
days=31;
break;
case 9:
days=30;
break;
case 10:
days=31;
break;
case 11:
days=30;
break;
case 12:
days=31;
break;
}
System.out.println(year+"年"+month+"月有"+days+"天");
}
}
}
结果如下：
