通过枚举变量的输入输出，枚举变量的值只能由赋值语句得到，不能用scanf函数直接读入，必要时可以先输入一个整数，然后通过switch语句给枚举变量赋值。
程序如下：
#include<stdio.h>
int main()
{
int n,d;
enum {sun,mon,tue,wed,thu,fri,sat}day;
char weekday[7][4]={"sun","mon","tue","wed","thu","fri","sat"};
printf("input today=");
scanf("%d",&d);
switch(d%7)
{
case 0:day=sun;
case 1:day=mon;
case 2:day=tue;
case 3:day=wed;
case 4:day=thu;
case 5:day=fri;
case 6:day=sat;
}
printf("input number=");
scanf("%d",&n);
printf("after %d day is :%s",n,weekday[(d+n)%7]);
return 0;
}
今天是10月11日星期二，运行结果为：
