I figured out my other problem, but...

I am still having some issues with this whole class thing in Visual C++ 6.0. Based on the code I am pasting below, is it best to create the app as a Win 32 Console App or just a Win 32 App? Also, I must be doing something wrong because the nature of the error messages I am getting lead me to believe that I am sourcing in my class (for lack of a better term) correctly. Any help that anyone could provide would be awesome... I'll paste the code and errors.

Main source code:

Code:

---

#include <iostream>
#include <string>
#include "square.h"
#include "ezwin.h"

using namespace std;


int ApiMain() {
        SimpleWindow Test;
          Test.Open();
        Square GreenSquare(Test);
        GreenSquare.SetColor(Green);
        GreenSquare.SetPosition(3.5,2.5);
        GreenSquare.SetSize(1.5);
       
        GreenSquare.Draw();
    cout << "Type a character followed by a\n" << "return to remove the display and exit" << endl;
        char AnyChar;
        cin >> AnyChar;
        Test.Close();
        return 0;
}

---

square.h (header file/class):

Code:

---

#ifndef SQUARE_H
#define SQUARE_H
#include "ezwin.h"

class Square {
        public:
                Square(SimpleWindow &W);
                void Draw();
                void SetColor(const color &Color);
                void SetPosition(float XCoord, float YCoord);
                void SetSize(float Length);
        private:
                color Color;
                float XCenter;
                float YCenter;
                float SideLength;
                SimpleWindow &Window;
};
#endif

---

Here are the errors, I created this app as a plain old Win 32 Application (totally blank):

test0422.cpp
C:\Program Files\Microsoft Visual Studio\MyProjects\pleasework\test0422.cpp(12) : error C2065: 'Square' : undeclared identifier
C:\Program Files\Microsoft Visual Studio\MyProjects\pleasework\test0422.cpp(12) : error C2146: syntax error : missing ';' before identifier 'GreenSquare'
C:\Program Files\Microsoft Visual Studio\MyProjects\pleasework\test0422.cpp(12) : error C2065: 'GreenSquare' : undeclared identifier
C:\Program Files\Microsoft Visual Studio\MyProjects\pleasework\test0422.cpp(13) : error C2228: left of '.SetColor' must have class/struct/union type
C:\Program Files\Microsoft Visual Studio\MyProjects\pleasework\test0422.cpp(14) : error C2228: left of '.SetPosition' must have class/struct/union type
C:\Program Files\Microsoft Visual Studio\MyProjects\pleasework\test0422.cpp(15) : error C2228: left of '.SetSize' must have class/struct/union type
C:\Program Files\Microsoft Visual Studio\MyProjects\pleasework\test0422.cpp(17) : error C2228: left of '.Draw' must have class/struct/union type
Error executing cl.exe.

pleasework.exe - 7 error(s), 0 warning(s)


Thanks!

this might be a dumb question but, is Square.h in the right directory?

There's no such thing as dumb questions, just dumb noobs like myself. :P

I did double check and square.h is in the same folder as my .cpp file (my main source code)

Is there a square.cpp file defining the fxns.

That there is not.. (a square.cpp file)... what should typically go into the .cpp file that I am lacking in the .h file? Forgive me if my questions seem a bit dense.. the book I am reading isn't real clear on this... thanks..

Also, does it matter in this case which application I choose to make this (either Win 32 App or Win 32 Console App)? I have tried it both ways and it seems like I get less errors trying it as a Win 32 App, so I have to figure that's the right way.... thanks again

Is the header file called SQUARE.H, Square.h, or square.h?

"Based on the code I am pasting below, is it best to create the app as a Win 32 Console App or just a Win 32 App?"

I don't know, but I think you should probably figure that out. I use Win32 Console App for most of my practice code, and Win32 app for a Windows program when not using MFC. My book says if you try to create a Windows program by creating a Win32 Console App, you're going to get errors, so maybe if you do it the other way around, like you seem to be doing, you'll get errors too.

The header file is actually called square.h

It sounds like I may want to do this as a console instead then? It seems like I had more problems with errors going that way, but if that's the right way I'll try it...

the .cpp file will contain the function definitions.

ex

Code:

---

// my .h file

class thing
{
    int function(int, float);

};


// my .cpp file

int thing::function(int i, float f)
{
    // do stuff here
  return something;
}

---

To do it as console use:

int main()

not

int ApiMain()

as the entry point.

The cpp file should contain function definitions for the methods of the Square class, whether you do this in console or not.

//////////////////////
//Square.cpp
/////////////////////
#include "Square.h"

Square(SimpleWindow &W);
{}
void Draw()
{}
void SetColor(const color &Color)
{}
void SetPosition(float XCoord, float YCoord)
{}
void SetSize(float Length)
{}

Just complete each function body within each {} as desired

"That there is not.. (a square.cpp file)... what should typically go into the .cpp file that I am lacking in the .h file?"

The functions declared in the .h file, have to be defined somewhere or how else is the program going to know what to do when a function is called?

It sounds like you're in way over your head with this program. I suggest you practice some simple Hello World type Win32 Console App programs first with everything in one file, and then learn how to create programs with multiple files. It appears classes are way down the road for you. It's better to start at the beginning and work your way through C++, than jump in towards the end and try to figure out what's going on.

"Just complete each function body within each {} as desired"

I seriously doubt the poster has any idea what you're talking about.

I don't have much experience with windows programming, but the poster's code looks like part of a win32 program to me.

Well, I guess I have to go back to the drawing board on this one... I have done quite a few simpler programs leading up to this one and haven't had any issues. I am sure that whatever I am doing wrong is right in front of my face and I just can't quite seem to get it yet. I will keep trying though!

"I have done quite a few simpler programs leading up to this one and haven't had any issues. "

Ok, I thought this might be the first program you've played around with. Did any of your previous programs involve functions? What about programs with multiple files? What type of projects were you creating for those?

Besides the type of project issues you're having, in your current program you have these functions declared in your class:

Square(SimpleWindow &W);
void Draw();
void SetColor(const color &Color);
void SetPosition(float XCoord, float YCoord);
void SetSize(float Length);

but where are those functions defined? Here is a simple function declaration:

void Double_and_Print(int a);

Here is the definition for that function:

Code:

---

void Double_and_Print(int a)
{
      cout<<2*a<<endl;
}

---

The C++ related stuff that I have done prior to this was pretty basic... programs that prompted for user input and output responses based on the input.. or programs that took user input and made a calculation of some sort and then output the answer.. nothing too major.. I have done some VB in the past (though some argue whether that's a real language LOL) and I've also done some regular C programming as well as Korn Shell Scripting in UNIX. I haven't actually done a whole heckuva lot in terms of functions in C++ yet though, but I have dealt with functions of course quite often in the other languages, so I have to figure it to be similar...

I think the declaring of the functions must be my missing piece. The problem in the book says to take the snippet of code which is basically the class Square portion and use that to create a program that draws a square with parameters defined in the problem... I don't know if I am making sense....

It's probably an exercise started for you. But you need to define the fxns.

What book is this? You might be missing something..

Yeah, it's not real specific about defining functions though. In fact, none of the examples in the book show defining the functions or making a seperate .cpp in addition to the .h file for the class. The book is entitled "C++ Program Design" by James Cohoon and Jack Davidson. It looks like it was originally published back in '97..

I'm still wondering how you decided what type of project to create? You can't just randomly pick a type. Different types of programs are organized differently, and the compiler needs to know what type of program it's looking at. Windows programs(=programs that use windows to interact with the user)are totally different than console programs, which don't have a windows interface.

A windows program has two functions: WinMain() and WindowProc() which are seemingly unconnected. The Windows operating system serves to form the connection between the two. In a console program, there is one function called main() which is the kick off point for your program, and other functions are called from within main().

"I haven't actually done a whole heckuva lot in terms of functions in C++ yet though, but I have dealt with functions of course quite often in the other languages, so I have to figure it to be similar..."

I'm not sure it works that way. You have to implement functions in a specific way in C++ or else the program won't compile.

As for classes in general, you have to start learning about them with simple examples, and then you have to learn about constructors, destructors, copy constructors, and assignment operators and how they are affected by the types of your data members and function definitions.

"In fact, none of the examples in the book show defining the functions or making a seperate .cpp in addition to the .h file for the class."

Most beginning C++ books start off with function definitions in the same file as main(). Then after you learn where they can positioned in the main() file, you learn to separate them into separate files.

That totally makes sense.. I appreciate you all taking the time to respond to my questions... Can anyone suggest a good C++ book that I might be able to buy or borrow from the library that would discuss classes and functions a bit better? Or even a website? I think part of my problem is that this book doesn't seem all that great when compared to other programming books that I've read. I've read and re-read this chapter on classes at least 5 times and it still isn't quite sinking in... maybe it's just user error? :)

Ivor Horton's Beginning C++

If you want to eventually learn about windows programming(=programs that use windows to interface with the user) using MFC(=a library of classes that spare you from having to reinvent the wheel), then get Ivor Horton's Beginning Visual C++ 6, in which the first 12 chapters are a C++ tutorial, and the second half of the book moves into windows programming with MFC.