C char 在 if..else 中不起作用

Question

这个问题已经有答案了:

Why does a space in my scanf statement make a difference? [duplicate] (3 个回答)

已关闭 9 年前。

当我运行程序时，无论我输入什么 shape ，执行最后的else语句。

#include <stdio.h>

int main(void)
{
    char shape = 'a';
    printf("What shape do you want?\nEnter 's' for a Square, 'b' for a Box, 't' for a Triangle\n");

    while (shape != 's' && shape != 'b' && shape != 't')
    {
        scanf_s(" %c", &shape);

        if (shape == 's')
        {
            printf("You entered %c", shape);
        }

        else if (shape == 'b')
        {
            printf("You entered %c", shape);
        }

        else if (shape == 't')
        {
            printf("you entered %c", shape);
        }

        else
        {
            printf("Please enter 's' 'b' or 't'");
        }
    }
    return 0;
}

Answer 1

scanf_s 需要您要读取的字符数(因此是 _s)。尝试 scanf("%c", &shape, 1)。