Thread: C++ Funtion/Include Problems.

I have done this. When I compile, it tells me

[Linker error] undefined reference to `someFunc()'

I'm still checking everything over right now.

What compiler are you using? You have to make sure all the files are part of your project. In addition the file extensions must be correct: .h for the header file, and .cpp for the file with the definitions.

Using multiple files is not some alternative to classes. It has to do with program organization. If you had a class, you would organize your program the same way:

main.cpp:

Code:

#include "header.h"

int main()
{
	One myone;
	myone.display();

	Two mytwo(3.2);
	mytwo.show();
	
	return 0;
}

header.h:

Code:

#ifndef __HEADER_H__
#define __HEADER_H__

////CLASS ONE//////
class One
{
private:
	int num;

public:
	One(int n);
	One();
	void display();
};

//////CLASS TWO//////
class Two
{
private:
	double time;

public:
	Two(double t);
	Two();
	void show();
};

#endif //__HEADER_H__

definitions.cpp:

Code:

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

using namespace std;

////DEFINITIONS/////

One::One(int n)
{
	num = n;
}

One::One()
{
	num = 0;
}

void One::display()
{
	cout<<num<<endl;
}

Two::Two(double t)
{
	time = t;
}

Two::Two()
{
	time = 1.0;
}

void Two::show()
{
	cout<<time<<endl;
}

You don't have to organize your code that way. Instead, you can just include everything in one file, which I suggest you do if you are having too much trouble with the multiple file concept. For instance, the same program above contained in a single file:

Code:

#include <iostream>
using namespace std;

////CLASS ONE//////
class One
{
private:
	int num;

public:
	One(int n);
	One();
	void display();
};

//////CLASS TWO//////
class Two
{
private:
	double time;

public:
	Two(double t);
	Two();
	void show();
};

//////MAIN//////////
int main()
{
	One myone;
	myone.display();

	Two mytwo(3.2);
	mytwo.show();
	
	return 0;
}

////DEFINITIONS/////

One::One(int n)
{
	num = n;
}

One::One()
{
	num = 0;
}

void One::display()
{
	cout<<num<<endl;
}

Two::Two(double t)
{
	time = t;
}

Two::Two()
{
	time = 1.0;
}

void Two::show()
{
	cout<<time<<endl;
}