Thread: Classes, inheritance and over-riding

I've C knowledge, but newish to C++. I am trying to learn Orge 3D, which heavily uses OOP.

Can anyone explain the constructor of the following class?

Code:

class CameraTrackListener: public ExampleFrameListener
{
protected:
public:
    CameraTrackListener(RenderWindow* win, Camera* cam)
        : ExampleFrameListener(win, cam)
    {
    }

    bool frameStarted(const FrameEvent& evt)
    {

        mAnimState->addTime(evt.timeSinceLastFrame);

        // Call default
        return ExampleFrameListener::frameStarted(evt);
        

    }
};

Run this code and see what happens:

Code:

class A
{
public:
    A(int n) {cout << "A constructor - " << n << endl;}
};

class B : public A
{
public:
    B(int n) : A(n) {cout << "B constructor - " << n << endl;}
};

int main()
{
   B b(5);

   return 0;
}

Then, get yourself a good C++ book. You're halfway there if you already know C.

gg

Cheers dude, can you recommend a book?

I've read the tutorials on this site, but they didn;t address this particular question

Cheers, I got constructors sorted.

Next, I thought functions from parent classes got inhirited?

If so, can somebody correct the following code snipit please

Code:

#include <iostream.h>

class mploygon
{
   public:
   mploygon ()
   {
   }
   mploygon(int a, int b)
   {
      cout << "Total = " << a + b << endl;
   }

   bool Area(int a, int b)
   {
      cout << "Area = " << a * b << endl;
      return (1);
   }
};

class mTriangle : mploygon
{
   public:
   mTriangle(int a, int b) : mploygon (a,b)
   {
      cout << "This is the triangle constructor" << endl;
   }
};

int main()
{
   mTriangle * b = new mTriangle(5,5);
   b->Area(5,5);

   return(0);
}

The dodgy line is ;

Code:

b->Area(5,5);

• "mploygon" => "mPolygon"? mVarName is usually used for hungarian notation for a member variable, not class name
• "class mTriangle : mploygon" == "class mTriangle : private mploygon" - which means you can't access mploygon members through an instance of mTriangle.
• "mTriangle * b = new mTriangle(5,5);" - You better delete that!!

Cheers dudes.

As you can tell i'm a serious noobie, but this is a very friendly forum!!!