switch(常量表达式){
case 表达式1:
[....];
break;
case 表达式:
.
.
.
default:
[....];
}
- switch(表达式)中表达式的值必须是下述几种类型之一:byte,short,
char,int,枚举 (jdk 5.0),String (jdk 7.0); case子句中的值必须是常量,不能是变量名或不确定的表达式值;
- 同一个switch语句,所有case子句中的常量值互不相同;
- break语句用来在执行完一个case分支后使程序跳出switch语句块;如果没有break,程序会顺序执行到switch结尾
- default子句是可任选的。同时,位置也是灵活的。当没有匹配的case时,执行
import java.util.Scanner;
public class Day04SwitchCase2 {
public static void main(String[] args) {
Scanner scan =new Scanner(System.in);
System.out.println("请输入年 月 日");
int year=scan.nextInt();
int month = scan.nextInt();
int day=scan.nextInt();
String time=year+"年"+month+"月"+day+"日";
int sumDays=0;
switch(month){
case 12:
sumDays=30;
case 11:
sumDays+=31;
case 10:
sumDays+=30;
case 9:
sumDays+=31;
case 8:
sumDays+=30;
case 7:
sumDays+=31;
case 6:
sumDays+=31;
case 5:
sumDays+=30;
case 4:
sumDays+=31;
case 3:
if((year%4==0&&year%100!=0)||year%400==0)
{
sumDays+=29;
}else{
sumDays+=28;
}
case 2:
sumDays+=31;
case 1:
sumDays+=day;
}
System.out.println(time+"是当年的第多少天?"+sumDays);
scan.close();
}
}