Example of indexed array declarations in c

smarter_c_array.c

#define ERROR_ALPHA 1
#define ERROR_BETA  4
#define ERROR_GAMMA 3
#define ERROR_DELTA 2

static const char *const strerr[] = {
   [ERROR_ALPHA] = "Error Alpha",
   [ERROR_BETA]  = "Error Beta",
   [ERROR_GAMMA] = "Error Gamma",
   [ERROR_DELTA] = "Error Delta",
};

Note that the order of the items in the array declaration don't have to match. I believe any gaps in the indexing should be initialized as if memclr().