如何从C中返回指针的函数打印字符串？

Question

This is my program in C:

#include <stdio.h>

char const* voice(void){
  return "hey!";
}

int main(){
const char* (*pointer)(void);
pointer = &voice;


printf ("%s\n", *pointer); // check down *
return 0;
}

• *with this i'm trying to print what is returning from pointer but it seems like not working.

What am I doing wrong?

Answer 1

You need to call the function pointers, ie use parenthesis:

#include <stdio.h>

char const* voice(void){
  return "hey!";
}

int main(){
const char* (*pointer)(void);
pointer = &voice;


printf ("%s\n", pointer());
//              ^^^^^^^^^
return 0;
}

* isn't needed for function pointers. (neither is & )

Answer 2

You call a function through a pointer in the same exact way that you call a function directly, as if that pointer was function's name:

printf ("%s\n", pointer());

Starting with the ANSI C standard, the asterisks and ampersands around function pointers are optional.