"undefined reference to" in G++ Cpp

Question

Can't seem to get the errors to go away. Errors are below. I have looked on google and still can't figure it out. It is not like I am new to Cpp, but have not fooled with it in a while.

Weird thing is it worked with G++ in Windows...

Errors:

• [ze@fed0r! ---**__*]$ g++ main.cpp
• /tmp/ccJL2ZHE.o: In function `main':
• main.cpp:(.text+0x11): undefined reference to `Help::Help()'
• main.cpp:(.text+0x1d): undefined reference to `Help::sayName()'
• main.cpp:(.text+0x2e): undefined reference to `Help::~Help()'
• main.cpp:(.text+0x46): undefined reference to `Help::~Help()'
• collect2: ld returned 1 exit status

main.cpp

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

using namespace std;

int main () {

    Help h;
    h.sayName();

    // ***

    // ***

    // ***
    return 0;

}

Help.h

#ifndef HELP_H
#define HELP_H

class Help {
    public:
        Help();
        ~Help();
        void sayName();
    protected:
    private:
};

#endif // HELP_H

Help.cpp

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

using namespace std;

Help::Help() { // Constructor
}

Help::~Help() { // Destructor
}

void Help::sayName() {
    cout << "            ***************" << endl;
    cout << "   ************************************" << endl;
    cout << "              ************" << endl;
    cout << "         *********************" << endl;
}

Answer 1

g++ main.cpp Help.cpp

You have to tell the compiler all the files that you want it to compile, not just the first one.