Question

wikipedia article on C states that Function and data pointers permit ad hoc run-time polymorphism.

what is the meaning of this?please explain.

Answer 1

Examine following code:

#include <stdio.h>

typedef int (*Func)(int a, int b);
int sum(int a, int b) {
    return a + b;
}

int substruct(int a, int b) {
    return a - b;
}

int main(int argc, char** argv){
    Func f = sum;
    printf("%d\n", f(1, 2));

    f = substruct;
    printf("%d\n", f(1, 2));
}

output:

3
-1

here I demonstrated how assigning different functions to a pointer can change the behavior of a program. This is kind of polymorphism.