Question

why do i need pointers to function ?

Answer 1

Among other uses, if you need to pass a function to a function as an argument, then function pointers are the only way to go

Answer 2

\[#
typedef void(*sorting_algorithm)(int*, size_t);
void test_sorting_algorithm(int* A, const size_t N, sorting_algorithm sort, const char* sort_name)
{
printf("Before %s: ", sort_name);
print_array(A, N);
sort(A, N);
printf("After %s: ", sort_name);
print_array(A, N);
}\]

in the example above, sorting_algorithm (and subsequently sort in the test_sorting_algorithm() parameter list) is a pointer to a function, that takes a pointer to int and a size_t parameter, and returns void.

If I want to invoke different runtime behavior depending on what sorting algorithm I decide to pick, this is one way to do it.

Answer 3

In general, function pointers allow a function to call another function that is unknown to it at compile time. You can pass a function pointer to some code and the function you pass can be called under certain conditions.