inheredance

Hi ! :) I try to break my c++ programe to .H and .cpp files. But my programe use heredity, and whene i break the prog into files I do not know how i will do it . Also my g++ compiler warning me in constractor line redwfinition. Any one who knows?

Thanks. Sorry for my english

put each class in a seperate .H and .cpp's, and have child classes include the header file of its parent class.

Code:

---

// ChildClass.H
#include "ParentClass.H"

class ChildClass : public ParentClass
{};

---

Or you can use a forward declaration

Code:

---

// ChildClass.H
class ParentClass;

class ChildClass : public ParentClass
{};

---

Use one or the other, not both.

>> Or you can use a forward declaration
You cannot use a forward declaration for inheritance. The first example is the way to go.

As for the redefinition warning/error, you should copy and paste the error message and the lines of code it points to so we can see it.

Quote:

---

You cannot use a forward declaration for inheritance.

---

Good call.

I put
---------------------------
#ifdef _class
#define _class

<class code>



#endif

---------------------------

Thanks for the help boys.

I will try yours way too.

That should be:

#ifndef

So you know what's going on:

Code:

---

#ifndef  _class_h_  // if _class_h_ is not defined
                    // Do everything following...
#define _class_h_    // define _class_h_

// Class code

#endif // end of the if statement

---

>> #ifndef _class

Generally, symbols used for include guards are done in all capital letters. Also, words with an underscore followed by a capital letter are reserved for use by your compiler implementation. So I would use something like CLASS_H or CLASS_H_.

Thanks boys.

I want to know more about preprocessors directives in c and c++.
Where can I find tutorials?

Do a google, or get a good book. As a side note, try looking at the header files in your compiler directory folder. It is not advised that you change the code, but looking at it will give you a good platform

Thanks