在C中使用枚举

Question

I have this enum:

  enum Seasons{
  winter,spring,summer,autumn
  };

what will this code do?

 enum Seasons curr_season;
 curr_season = autumn;
 curr_season = 19;

Thank you!

Answer 1

enum Seasons{
    winter,spring,summer,autumn
};

The above creates the following

winter=0, spring=1, summer=2 and autumn=3

NOTE: enums are just integers! .. It can take negative numbers also!

enum Seasons curr_season;
curr_season = autumn;
/* curr_season will now have 3 assigned */

curr_season = 19;
/* curr_season will now have 19 assigned */

You can run the following code to check this!

#include <stdio.h>

enum Seasons{
        winter,spring,summer,autumn
};

void print_seanons(void)
{
    printf("winter = %d \n", winter);
    printf("spring = %d \n", spring);
    printf("summer = %d \n", summer);
    printf("autumn = %d \n", autumn);
    return;
}

int main(void)
{
    enum Seasons curr_season;
    print_seanons();

    curr_season = autumn;
    printf("curr_season = %d \n", curr_season);
    curr_season = 19; 
    printf("curr_season = %d \n", curr_season);
    return 0;

}

Answer 2

Enums constants are of type int in c. Although enum s are not explicitly of type int , the conversion between enumerated types, and int s is silent. There is usually no constraint checking on enums, so your code is functionally equivalent to:

int curr_season;
curr_season = 3;
curr_season = 19;

Answer 3

Enums are integral values, so it will assign the value 19 to curr_season .

Cross use (assigning integer values to an enum) is considered poor programming practice and should be avoided.