DaniWeb Forum Index > Software Development > C++

Error - Going from Java to C++

Please support our C++ advertiser: Programming Forums - DaniWeb Sister Site

•

Join Date: Feb 2009

Posts: 19

Reputation: icu222much is an unknown quantity at this point

Solved Threads: 0

icu222much icu222much is offline

Offline

Newbie Poster

Error - Going from Java to C++

Nov 6th, 2009

I have created a linked list in Java, and now I am trying to convert my program to C++.
When I try to compile, it gives me the error saying that 'next' uses 'CarNode' which is being defined. I am wondering if there is any way around this?

Java:

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
public class CarNode {
  public Car carObject;
  public CarNode next;
 
  public CarNode (Car newCar, CarNode newNext) {
    carObject = newCar;
    next = newNext;
  }
}
public class CarNode {
  public Car carObject;
  public CarNode next;

  public CarNode (Car newCar, CarNode newNext) {
    carObject = newCar;
    next = newNext;
  }
}

C++:

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
class CarNode: public Car {
  public:
    Car carObject;
    CarNode next;
 
    CarNode(Car newCar, CarNode newNext) {
      carObject = newCar;
      next = newNext;
  }
}
class CarNode: public Car {
  public:
    Car carObject;
    CarNode next;

    CarNode(Car newCar, CarNode newNext) {
      carObject = newCar;
      next = newNext;
  }
}

•

Join Date: Dec 2008

Posts: 1,460

Reputation: firstPerson is just really nice

Solved Threads: 189

firstPerson firstPerson is offline

Offline

Nearly a Posting Virtuoso

Nov 6th, 2009

I am a little doubtful about your code. Why does CarNode inherit from
Car and it also composes it ?

Note that in c++ objects is by default passed by value and Not passed by
reference. You may wan't to read about pointers and reference in c++.

Help with Code Tags

(Toggle Plain Text)

1) Prove that the area of a circle is pi*r^2, where "r" is the radius of the circle.
2) Problem 2[b]solved by : jonsca

•

Join Date: Feb 2009

Posts: 19

Reputation: icu222much is an unknown quantity at this point

Solved Threads: 0

icu222much icu222much is offline

Offline

Newbie Poster

Nov 6th, 2009

thank you.

•

Join Date: Jan 2008

Posts: 3,844

Reputation: VernonDozier has a reputation beyond repute

Solved Threads: 503

VernonDozier VernonDozier is offline

Offline

Senior Poster

Nov 7th, 2009

Yeah, I don't see the word "extends" in your Java code, so I'm doubtful of the inheritance. firstPerson is right regarding pointers and pass-by-value. I'd have to see the overall set-up, but you're probably looking for something ike:

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
class CarNode/*: public Car */
{
  public:
    Car* carObject;
    CarNode* next;
 
    CarNode(Car* newCar, CarNode* newNext) 
    {
      carObject = newCar;
      next = newNext;
  }
};
class CarNode/*: public Car */
{
  public:
    Car* carObject;
    CarNode* next;

    CarNode(Car* newCar, CarNode* newNext) 
    {
      carObject = newCar;
      next = newNext;
  }
};