C语言问题析之 enum union (二十一)

#include <stdio.h>

typedef enum{CLUBS=5,DIAMONDS=6,HEARTS,SPADES} Suit; //定义 enum 只能选择其中一个
Suit fun(char xx);//  定义一个函数

int main()
{
    //测试 union 大小4字节
      union {
    unsigned char a;
    int b;
    }number;

    number.a = 0xfe;
    printf("sizeof(union) is %d\n",sizeof(number));
    printf("%d\n",number.a);
    printf("%d\n",number.b);

    //测试 enum a b c 只能选择其中的一个
    enum weekday{sun,mon,tue,wed,thu,fri,sta}a,b,c;
    a = sun;
    b = mon;
    c = tue;
    printf("%d,%d,%d\n",a,b,c);

    if(fun(0)==5)
        printf("CLUBS\n");
    return 0;
}

Suit fun(char xx)
{
    if(xx == 0)
        return CLUBS;
    if(xx ==1)
        return DIAMONDS;
    if(xx ==2)
        return HEARTS;
    if(xx ==3)
        return SPADES;
}

ywx@ywx:~/yu/c$ ./test
sizeof(union) is 4
254
11313150
0,1,2
CLUBS
ywx@ywx:~/yu/c$