Function pointer in C

One pointer variable can point to another variable. 

Similarly one function can point another function. 

This method is helped in callback mechanism. i,e) passing function as argument to anther function.

#include <stdio.h>
int add(int, int);
 
int add(int var1, int var2)
{
 return var1 + var2;
}
 
int main(int argc, char **argv)
{
 int x = 0;
 int (*functionPtr)(int, int);
 functionPtr = &add;
 x = (*functionPtr)(10, 15);
 printf("%d\n", x);
 return 0;
}