Build C++ files: .h and .cpp

Question

We are trying to learn how to build a c++ file with .h and .cpp files. We keep getting the same error :error LNK2019: unresolved external symbol WinMain@16 referenced in function _ _tmainCRTStartup, and we don't know what we are doing wrong. Here is the code from our 3 files:

---

// First cpp file

#include "stdafx.h"
#include <iostream>
#include "chayaGradeBook.h.h"
namespace std;

//constructor
GradeBook::GradeBook (string name)
{
setCourseName(name);
}
void GradeBook::setCourseName(string name)
{
if (name.size() <= 25)
    courseName=name;
if (name.size() > 25)
{
    courseName = name.substr (0, 25);

    cerr << "Name \"" <<name<< "\"exceeds maximum length (25).\n"<< "Limiting courseName to first 25 charachters.\n"<<endl;
}
}

string GradeBook::getCourseName() const
{
return courseName;
}

void GradeBook::displayMessage() const
}  
cout << "Welcome to the grade book for \n" << getCourseName() << "!" <<endl;
}

---

// chayaGradeBook.h.h

#include <string>


//Grade Book class definition
class GradeBook
{
public:
explicit GradeBook (std::string);
void setCourseName (std::string);
std::string getCourseName() const;
void displayMessage() const;
private:
std::string courseName;
};

main.cpp file:

#include "stdafx.h"
#include <iostream>
#include "chayaGradeBook.h.h"
#include "chayaGradeBook.cpp"
using namespace std;


int main()
{
GradeBook gradeBook1 ("CS101 Introduction to Programming in C++");
GradeBook gradeBook2 ("CS102 Data Structures");

cout<< "gradeBook1's initial course name is: "
    << gradeBook1.getCourseName()
    <<"\ngradeBook2's inital course name is: "
    << gradeBook2.getCourseName()<< endl;

gradeBook1.setCourseName("CS101 C++ Programming");

cout <<"\ngradeBook1's course name is: "
    <<gradeBook1.getCourseName()
    << "\ngradeBook2's course name is: "
    << gradeBook2.getCOurseName() <<endl;
}

Answer 1

Linker can't find yours WinMain() which is an antry point for windows application. Create new console project and copy yours file into it this should help.

Answer 2

It is the peculiarity of Windows OS. Microsoft think that WinMain are better for "native Windows" applications (than main ) :-)
By the logic, "native Windows" applications are closely associated with Windows, based in the native Windows API and are not portable. It is likely a case of "freestanding environment" in terms of C++.
You need "console application project" in IDE...