枚舉C中的“未知類型名稱”

Question

它說未知類型名稱'week'..錯誤顯示在第三行。

這是我的代碼：

#include <stdio.h>

enum week{ sunday, monday, tuesday, wednesday, thursday, friday, saturday };


void lecture_unit(week day)
{
    if (day == friday) printf("COS10008\n");
    if (day == monday) printf("Maths\n");
    if (day == sunday) printf("Holiday\n");
}

int main()
{
    week today;
    today = sunday;
    lecture_unit(today);
    printf("Day %d\n",today);
    return 0;
}

Answer 1

正確的類型名稱應該是enum week而不是僅僅week

#include <stdio.h>

enum week{ sunday, monday, tuesday, wednesday, thursday, friday, saturday };


void lecture_unit(enum week day)
{
    if (day == friday) printf("COS10008\n");
    if (day == monday) printf("Maths\n");
    if (day == sunday) printf("Holiday\n");
}
int main()
{
    enum week today;
    today = sunday;
    lecture_unit(today);
    printf("Day %d\n",today);
    return 0;
}

如果您更喜歡使用week則可以使用typedef將類型enum week為week

#include <stdio.h>

enum week{ sunday, monday, tuesday, wednesday, thursday, friday, saturday };
typedef enum week week;

void lecture_unit(week day)
{
    if (day == friday) printf("COS10008\n");
    if (day == monday) printf("Maths\n");
    if (day == sunday) printf("Holiday\n");
}
int main()
{
    week today;
    today = sunday;
    lecture_unit(today);
    printf("Day %d\n",today);
    return 0;
}