枚举

什么是枚举？

-----把一个事物所有可能的取值一一列举出来。

枚举的优缺点？

-----代码更安全，但是书写麻烦

#include<stdio.h>

enum WeekDay
{
  MonDay,TuesDay,WednesDay,ThursDay,FriDay,SaturDay,SunDay  
};
void f(enum WeekDay i)
{
    switch(i)
    {
        case 0:
                printf("MonDay!\n");
                break;
        case 1:
                printf("TuesDay!\n");
                break;
        case 2:
                printf("WednesDay!\n");
                break;
        case 3:
                printf("ThursDay!\n");
                break;
        case 4:
                printf("FriDay!\n");
                break;
        case 5:
                printf("SaturDay!\n");
                break;
        case 6:
                printf("SunDay!\n");
                break;
    }
}
int main(void)
{
    //int day;//day定义成int类型不合适
    //enum WeekDay day=WednesDay;
    f(MonDay);
    return 0;
}