How to retrieve elements in an enum type variable?

Question

When the code is compiled, it doesn't show the values inserted to the enum variable in structure

This code only shows the keyboard input 0 or 1

#include<stdio.h>
#define Max_CHARS_NAME 100

struct gps_point{
    double latitude;
    enum latitude_pole {North,South} pole;
    double longitude;
    enum longitude {East,West} dire;
    char location_name[Max_CHARS_NAME];
}g;

int main(){
    char arr[Max_CHARS_NAME];
    int i = 0;

    printf("Enter location\n");
    scanf("%s", &g.location_name);  
    strcpy(arr,g.location_name);

    printf("Enter latitude\n");
    scanf("%lf", &g.latitude);

    printf("Enter latitude pole North - 0, South - 1\n");
    scanf("%d",&g.pole);

    //g.latitude_pole = g.pole;

    printf("Enter longitude dire East - 0, West - 1\n");
    scanf("%d", &g.dire);

    printf("Enter longitude\n");
    scanf("%s", &g.longitude);

    printf("%s is situated at (Latitude : %s %lf , Longitude: %s %lf). \n",arr,g.pole,g.latitude,g.dire,g.longitude);

    return 0;
}

Answer 1

See the below example,

enum week{Mon, Tue, Wed, Thur, Fri, Sat, Sun}; 

int main() 
{ 
    enum week day; 
    day = Wed; 
    printf("%d",day); 
    return 0; 
}  

Here we declare a variable day of type week and assign one(numerical) value in the list to the variable using a "string" but it isn't possible to do the other way.

Answer 2

This is equivalent to

enum latitude_pole {
  North = 0,
  South = 1
} pole;

This defines the variable pole whose possible values are North(0) and South(1).

It is equivalent to writing

enum latitude_pole {
  North = 0,
  South
} pole;

because in case you initialize one member the next one will be +1 (previous member).

In your code the missing of initialization will have it insert by default the value 0 for the first member and 1 for the second member.

Answer 3

If you don't give the enumeration constants any values, the compiler will do it silently.

The first one will always be given value 0 , and every following enumeration constant will get the value of previous constant + 1.

In your case {North,South} , North is guaranteed to be 0 and South guaranteed to be 1. The type of these enumeration constants is guaranteed to be 100% compatible with int .

Had you typed only some values explicitly, the rule where every constant getting the value of the previous + 1 is still applicable. So if you would do {North,South,East=5,West} , they would get the values 0, 1, 5, 6 .