Question

I’ve hit my first assignment requiring object oriented programs. I started working on the (rather large and complicated) project and hit a few snags when it came to linking multiple class files and their associated .h files. Basically I keep getting “Multiple Definition of Class” errors, even though I have my Include guards and theres no Global Variables. I won’t post my code for the assignment itself, but here’s a much simplified example giving me an identical error:

//Runner file.
#include "Class1.cpp"
int main(){
    Class1 classtest();
    return 0;
}

–

//Class1.h
#ifndef CLASS1_H
#define CLASS1_H
class Class1
{
    public:
        Class1();
};
#endif // CLASS1_H

–

//Class1.cpp
#include "Class1.h"
#include <iostream>
#include "Class2.cpp"
using namespace std;
Class1::Class1()
{ 
    cout << "Created Test Class1";
    Class2 testClass();
}

And then nearly identical Class2 files

//Class2.h
#ifndef CLASS2_H
#define CLASS2_H
class Class2
{
    public:
        Class2();
};
#endif // CLASS2_H

–

#include "Class2.h"
#include <iostream>
using namespace std;

Class2::Class2()
{
    cout << "Created Class 2";
}

The whole thing then generates around 1.4 metric craptons of errors, most of which are in the format:
obj\Debug\Runner.o||In functionClass2′:|C:\Users\MikeD\Desktop\C++\ObjectOTesting\Class2.cpp|6|
multiple definition ofClass2::Class2()'|
obj\Debug\Class2.o:C:\Users\MikeD\Desktop\C++\ObjectOTesting\Class2.cpp|6|first defined here|

I KNOW I’m doing something stupid here, but I haven’t been able to find out what exactly. Any help is really appreciated.

Answer 1

You don’t #include CPP files — you compile them. CPP files, in turn, #include H files.