I have an enumeration in C as follows:

enum menu
{
    PASTA,
    PIZZA,
    DIET_COKE,
    MOJITO,
};

Since I haven't explicitly mentioned the integer values corresponding to these elements, they are assigned values 0,1,2, and 3 respectively.

Say I decide to add another 100 or so items to my enum. Then is there a way to access these elements by the number they are associated with? (Like how we can access an element of an array using its index)

CodePudding user response：

The enums are nothing but named constants in C. Same as you declare a const using

#define PASTA 0
#define PIZZA 1
#define DIET_COKE 2
#define MOJITO 3

for example.

With the enum the compiler does that for you automatically. So there is no way to access enums in a way you want in C, unless you create an array for them.

Update for an example

An example use case to show how do you implement a string list with the accompany of enum as index:

#include <stdio.h>

char *stringsOfMenu[] = {
    "Pasta",
    "Pizza",
    "Diet Coke",
    "Mojito"
};

enum menuIndex {
    PASTA,
    PIZZA,
    DIET_COKE,
    MOJITO
};

int main(void) {
    
    // For example you show menu on the screen first
    puts("Please select");
    puts("-------------");
    for(int i = 0; i <= MOJITO; i  ) {
        printf("[%d] - %s\n", i 1, stringsOfMenu[i]);
    }
    putchar('\n');
    printf("Make a choice: ");
    int choice = -1;
    scanf("%d", &choice);
    
    if(choice <= 0 || choice > MOJITO 1) {
        puts("Not a valid choice");
        return 1;
    }
    
    // Note that the choice will contain the counting number.
    // That's why we convert it to the index number.
    printf("Your choice %s is in progress, thank you for your patience!\n", stringsOfMenu[choice-1]);
    return 0;
}

This is an output demo:

Please select
-------------
[1] - Pasta
[2] - Pizza
[3] - Diet Coke
[4] - Mojito

Make a choice: 2
Your choice Pizza is in progress, thank you for your patience!