//enum  --  枚举值
# include <stdio.h>
# include <string.h>   // 为了使用strcmp()
# define LEN 30

enum spectrum {red, orange, yellow, green, blue, violet};
const char * colors[] = {"red", "orange", "yellow", "green", "blue", "violet"};

int main(void)
{
    char choice[LEN];
    enum spectrum color;
    int color_is_found = 0;

    puts("Enter a color (empty line to quit): ");

    while(gets(choice) != NULL && choice[0] != '\0')
    {
        printf("choice1 = %s.\n",choice);

        for(color = red; red <= violet; color++)
        {
            printf("choice2 = %s.\n",choice);
            if(strcmp(choice,colors[color]) == 0)
            {
                color_is_found = 1;
                break;
            }
            else
                color_is_found = 0;
        }
        printf("choice3 = %s.\n",choice);
        printf("color_is_found = %d.\n",color_is_found);

        if(color_is_found == 1)
        {
            switch(color)
            {
            case red    : puts("Roses are red.");
                break;
            case orange : puts("Poppies are orange.");
                break;
            case yellow : puts("Sunflowers are yellow.");
                break;
            case green  : puts("Grass are green.");
                break;
            case blue   : puts("Bluebells are bllue.");
                break;
            case violet : puts("Violets are violet.");
                break;
            }
        }
        else
            printf("I don't know about the color %s.\n",choice);

        color_is_found = 0;
        puts("Next color,please (empty line to quit): ");
    }

    puts("Goodbye!");

    return 0;
}

请问这个程序哪里出错了呀，我实在是找不到
------ 这句话没必要说

当输入的颜色与枚举中的一样时，程序正常运行，但当输入值与枚举值不一样时，程序停止运行，不返回所规定值
------ 与其让别人猜什么叫“输入的颜色与枚举中的一样”，什么叫“正常运行”，……
不如直接说“输入fuck，期待输出I don't know about the color fuck.，实际运行出错。”

red <= violet 改为 color <= violet

while中的for循环变量？
for(color = red; red <= violet; color++)
        {
            printf("choice2 = %s.\n",choice);
            if(strcmp(choice,colors[color]) == 0)
            {
                color_is_found = 1;
                break;
            }
            else
                color_is_found = 0;
        }


另外for循环color可以定义为int型即 for（color=0；color<=5;color++）....
不然在VC6.0中编译不过

估计你用的是C++编译器