Question

I need your help in writing a efficient program.

I have approx 50 functions say call_1(), call_2() … call_50(). I need to call them based on the index read from a data packet, i.e if the field in data is 25 in need to call call_25(), if 10 then call_10().

I have written this in if else condition like

if (index == 5) 
    call_5() 
elseif (index == 6)
   ..so on .. 

But I think this is not the efficient way of writing. Any other ideas of implementing this scenario?
Can function pointers help here?
Appreciate your help. thanks.

Answer 1

Yes, use a lookup table of function pointers:

typedef void(*fp)(void);

void call_01(void);
void call_02(void);
/* ... */

fp functions[] = { &call_01,
                   &call_02,
                   /* ... */
                 };

void call()
{
    unsigned int n = get_index();
    functions[n]();
}