Question

i am trying to run a very simple C program using XCode which is typed below

1)   #include <stdio.h>
2)   int main ()
3)   {
4)     printf("Hello, World!\n");
5)     func();
6)     return 0;
7)   }
8)   void func()
9)   {
10)    printf("xxxx");
11)  }

In line number 5 i am getting warning “Implicit declaration of func is invalid in c99” and in line number 8 i am getting an error “conflicting types for func”

please advise
Thanks,

Answer 1

You need to declare func(); before using it (in main), otherwise it is declared as a function that returns int, and when the compiler gets to line 8, it sees a different declaration of the same function that returns void.

#include <stdio.h>
void func(void);
int main ()