第 14 章 结构和其他数据形式（enum枚举）

 /*-----------------------------
     enum.c -- 使用枚举类型的值
 -----------------------------*/

 #include <stdio.h>
 #include <string.h>
 //#include <stdbool.h>    //C99特性

 #define LEN 30

 char* s_gets(char *st, int n);

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

 int main()
 {
     char choice[LEN];
     int color;
     bool color_is_found = false;

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

     while (s_gets(choice, LEN) != NULL && choice[] != '\0')
     {
         for (color = red; color != violet; ++color)
         {
             if (strcmp(choice, colors[color]) == )
             {
                 color_is_found = true;
                 break;
             }
         }

         if (color_is_found)
             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 is green");
                 break;
             case blue:
                 puts("Bluebells are blue");
                 break;
             case violet:
                 puts("Violets are violet");
                 break;
             }
         else
             printf("I don't know about the color %s.\n", choice);

         color_is_found = false;

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

     puts("Goodbye");

     return ;
 }

 char* s_gets(char *st, int n)
 {
     char *ret_val, *find;

     if (ret_val = fgets(st, n, stdin))
     {
         if (find = strchr(st, '\n'))
             *find = '\0';
         else
             while (fgetc(stdin) != '\n') continue;
     }

     return ret_val;
 }

enum.c