Undefined Reference to

Question

When I compile my code for a linked list, I get a bunch of undefined reference errors. The code is below. I have been compiling with both of these statements:

Answer 1

1. Usually headers guards are for header files (i.e., .h ) not for source files ( i.e., .cpp ).
2. Include the necessary standard headers and namespaces in source files.

LinearNode.h:

#ifndef LINEARNODE_H
#define LINEARNODE_H

class LinearNode
{
    // .....
};

#endif

LinearNode.cpp:

#include "LinearNode.h"
#include 
using namespace std;
// And now the definitions

LinkedList.h:

#ifndef LINKEDLIST_H
#define LINKEDLIST_H

class LinearNode; // Forward Declaration
class LinkedList
{
    // ...
};

#endif

LinkedList.cpp

#include "LinearNode.h"
#include "LinkedList.h"
#include 
using namespace std;

// Definitions

test.cpp is source file is fine. Note that header files are never compiled. Assuming all the files are in a single folder -

g++ LinearNode.cpp LinkedList.cpp test.cpp -o exe.out