Question

—UPDATED —

I have problems when including headers and cpp files in my project, so here are the files:
Person.h

#ifndef PERSON_H
#define PERSON_H

class Person {
private:
string firstName;
string lastName;
long NID;

public:
Person();
void toString();

string get_firstName() {
    return firstName;
}

string get_lastName() {
    return lastName;
}

long get_NID() {
    return NID;
}
};

#endif

Teacher which extends Person
Teacher.h

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

#ifndef TEACHER_H
#define TEACHER_H

class Teacher : public Person {
private:
int avg_horarium;

public:
Teacher();
void toString();

int get_avg_horarium() {
    return avg_horarium;
}
};

#endif

Then here is Teacher.cpp:

#include "Teacher.h"
using namespace std;

Teacher::Teacher() : Person() {
cout << "Enter average monthly horarium: ";
cin >> avg_horarium;
}

void Teacher::toString() {
Person::toString();
cout << "Average monthly horarium: " << avg_horarium;
}

The other class which extends Person is Student and since it’s similar to teacher i won’t poste it here. My question is what am i doing wrong to get all these errors on the screenshot:
http://s14.postimage.org/45k08ckb3/errors.jpg

Answer 1

The problem is your incorrect treatment of stdafx.h file. In MSVC compilers, when precompiled headers are enabled, everything before #include "stdafx.h" line is ignored.

Firstly, stop including stdafx.h into header (.h) files. stdafx.h is supposed to be included into implementation (.cpp) files. In your case, #include "stdafx.h" should be placed into Person.cpp and Teacher.cpp, not into Person.h and Teacher.h.

Secondly, either disable precompiled headers in your project, or make sure that #include "stdafx.h" is always the very first meaningful line in each of your implementation files. All other #include directives should go after #include "stdafx.h", not before.