Question

I have two files:

hello.h and hello.cpp

hello.h

#ifndef __HELLO_H__
#define __HELLO_H__

using namespace std;

void PrintMessage();

#endif

hello.cpp

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

using namespace std;

void PrintMessage()
{
     cout << "I want to be displayed!";
}

Now, I want to use PrintMessage() in a new .cpp file, but I keep getting an error message. This is what I’m doing:

printingmessage.cpp

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

using namespace std;

int main()
{
     PrintMessage();
     return 0;
}

Am I just doing something blatantly wrong? I do have all of them in the same folder; I assume it has something to do with Dev-C++ (what I’m using to write/compile/run), but I can’t figure it out. Anyone have any ideas?

---

I created a folder on my desktop, put all three files inside, and I tried to compile my printingmessage.cpp file exactly as it is. This is the error I’m getting:

[Linker error] Undefined reference to 'PrintMessage()' 

Answer 1

i don’t know dev C++ , but i would strongly advise if you do any serious coding to learn/move to the terminal and use make files, or a newer IDE such as visual studios.

heres a short script you can run save it as bash.sh
something like this

g++ hello.cpp -O2 -g -c 
g++ hello.o printmessage.cpp -Wall -O2 -o print

then run it with ./print