Passing function pointer as argument

[Allan.d]

I read the tutorial on function pointers, the arguments of the declaration of the pointer is not clear. The following code does not work :

# include <stdio.h> 
  int (int a, int b)
 (
     return a * b;
 )   
 
  int (int c, int d)
 (
     return c / d;
 )
 
 int main ()
 (
     int a = 20;
     int b = 20;
     int d = 100;
   
     int (* p) (int, int) = NULL;
     p = & function2;
   
     int (* p2) (int, int) = NULL;
     p2 = & function3;
   
     int (* t [2]) () = (p (a, b), p2 (p (a, b), d)) 
 
     printf ( "Result:% d \ n", (* p) (a, b));
     printf ( "Result:% d \ n", (* p2) (p (a, b), d));
   
     printf ( "\ n");
   
     printf ( "Result:% d \ n", t [0 ]()); 
     printf ( "Result:% d \ n", t [1 ]());   
   
     getchar ();
     return 0;
 )

[Zecho]

By cons libraries function that you can do...

void func (int x, int y);

 boost:: function <void (int) f = boost:: bind (& func, 5);
 f (6) / / calls func (5, 6)

[Walby]

#include <string.h>
#include <stdlib.h>

void func(int (*comp)()) {
    char *g="123";
    char *f="234";
    if( comp(g,f)!=0 ) { 
        printf("pointer");    
    }
}

int main() {
  
  func( strcmp );

  return EXIT_SUCCESS;
}

[Aberto]

Passing a function pointer as an argument to a function is quite essential when you want to implement callback functions. Passing function pointers to a DLL has been done for generations.A function pointer is a variable that stores the address of a function that can later be called through that function pointer.