A fair amount, I would like this to happen any suggestions?

-DpDb

Wow thank you baavgai that was very helpful. So, I guess I was wrong in assuming I needed a header file in linking C++ with C. Was I right in assuming C can only be correctly linked to the correct libs with gcc? and what is the test file is in an output file or an object file? If I'm basically concatenating two different object files into test. Or, am I complete wrong in thinking that.

DpDb

Can you not compile C code with g++ as well just have linking issues with not getting the correct C libs? I thought that was the difference.

and here is my current C code:

#include "callHello.h"
#include <stdio.h>

//extern "C" const char* sayingHello();

int main(void){

   sayingHello();

   printf("this is the programming language C");

   return 0;
}

and the header file callHello.h:

#ifndef _callHello
#define _callHello

#ifdef __cplusplus
extern "C"{
#endif

void sayingHello();

#ifdef __cplusplus
}
#endif

#endif /*callHello wrapper*/

current C++ code:

#include "callHello.h"
#include <iostream>

using namespace std;



//public:

extern "C"{

  void sayingHello(){
  
    cout << "Hello from the C++ Language - Hello!!";
  
    //return "Hello from the C++ Language - Hello!!";
  }
}

commandline:

$ g++ -c callHello.cpp
$ ar rvs callHello.a callHello.o
$ g++ call.c -l callHello.a
call.c: In function ‘int main()’:
call.c:8: error: ‘sayingHello’ was not declared in this scope

The C header file and the C file have not changed

DpDb

and yeah I don't know what I was thinking when I was trying to make a class there. Guess I was grabbing at straws.

DpDb

I believed that if I compiled call.c with g++ it would not link the proper C libs aka stdio.h guess that was a bad assumption.

DpDb

So I removed my naive approach to putting my extern C inside of a class and it compiled fine. But now I get this:

$g++ call.c -l callHello.a
call.c: In function ‘int main()’:
call.c:8: error: ‘sayingHello’ was not declared in this scope