Do not #include
anything in your header file. And do a #include "kontaktverzeichnis.h"
in the kontaktfunktionen.c
file.
As @StoryTeller commented, define your kontakt_hinzufuegen()
as int kontakt_hinzufuegen()
in the kontaktfunktionen.c
file and return an int
value from the function kontakt_hinzufuegen
as for ex::
#include <stdio.h>
#include "kontaktverzeichnis.h"
// define the type for this array as below
int kontakt[];
int kontakt_hinzufuegen(){
int i = 0;
printf("Bisher sind %i Kontakte angelegt.",kontakt[i]);
kontakt[i++];
// Return an int value
return 0 ;
}