Introduction

This note introduces a way to initiliaze an item in an array by its index.

Using index to init specific item in an array

#include <stdio.h>

enum {
    TYPE_1,
    TYPE_2,
    TYPE_3,
};

static int array[] = {
    [TYPE_1] = 1,
    [TYPE_3] = 4,
};

int main()
{
    printf("hello world %d %d\n", array[1], array[2]);
}

This is usefuly to insert a new enum type, say if I will change to

enum {
    TYPE_1,
    TYPE_1_1,
    TYPE_2,
    TYPE_3,
};

The original code still works.