Expert: Narendra - 7/11/2006

Question
in an interview i was asked to write a program which receives 3 values and selects a function according to the value received? For eg., funcion A if 1 is received, function B for 2 and function C for 3. I was asked to do this with function pointers.
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Followup To

Question -
What are function pointers? Why is it used? how can we use function pointer instead of switch-case?

Answer -
What are function pointers?
Function pointers are basically pointers.
Instead of holding an address of data, it holds the address of a function.

Why is it used?
To indirectly call functions.
Callbacks are implemented using this mechanism.

how can we use function pointer instead of switch-case?
No, they are not a replacement for switch-case.

Answer
int fun()
{
}

calling_fn(int ch)
{
    // Declare your function pointer here, say *fn.

    switch (ch)
    {
    case 1: fn = A;
         break;
    case 2: fn = B;
         break;
    case 3: fn = C;
         break;
    }

    fn();
}