Why does this C++ link not work? (OSX Mavericks)

Question

I am learning C++. I have tried linking separate files in an attempt to have a class in a seperate file.

When I build and run the program I get this error message:

Undefined symbols for architecture x86_64: "Sally::printCrap()", referenced from: _main in Main-8bfa94.o "Sally::Sally()", referenced from: _main in Main-8bfa94.o ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation) [Finished in 0.3s with exit code 1]

Here is my code:

Main.cpp

#include <iostream>
#include <string>

#include "Sally.h"

using namespace std;

int main()
{
    Sally sallyObject;
    Sally *sallyPointer = &sallyObject;

    sallyObject.printCrap();
    sallyPointer->printCrap();
}

Sally.h

#ifndef SALLY_H
#define SALLY_H

class Sally
{
public:
    Sally();
    void printCrap();
};

#endif

Sally.cpp

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

using namespace std;

Sally::Sally()
{

}

void Sally::printCrap(){
    cout << "Crap \n";
};

Any help would be greatly appreciated!

How do you compile the program? Can you post the command you use? My guess is that you don't compile Sally.cpp (and therefore you don't link it). Try g++ main.cpp a.cpp — vsoftco

vsoftco vsoftco · Accepted Answer · 2014-07-23T01:37:52

Just launch the Terminal application of OS X, then type

cd "/Users/BEASTMACHIENEjr/Desktop/C++ Files" to go to that folder, then type g++ Main.cpp Sally.cpp. This will produce a file called a.out, which you can then launch by typing ./a.out

PS: if you use Sublime Text, I recommend creating a Makefile so you can compile code spanned across multiple source files.

Why does this C++ link not work? (OSX Mavericks)

1 Answers