Homework 5
C++ Programming /
Deadline is November 20

Exercise 1: Given the following C++ code: class A { public : int x; A *objARef; private : int y; protected : int z;
};
class B : public A { public : A objA;
};
class C { public : A objA; A *objARef; B objB;
};

Determine for each of the following attribute-access-expressions whether it results in an Error (Wrong) or not (OK).

| |in class A |in class B |in class C |
|x |[pic] |[pic] |[pic] |
|y |[pic] |[pic] |[pic] |
|z |[pic] |[pic] |[pic] |
|objA.x |[pic] |[pic] |[pic] |
|objA.y |[pic] |[pic] |[pic] |
|objA.z |[pic] |[pic] |[pic] |
|objARef->x |[pic] |[pic] |[pic] |
|objARef->y |[pic] |[pic] |[pic] |
|objARef->z |[pic] |[pic] |[pic] |
|objB.x |[pic] |[pic] |[pic] |
|objB.y |[pic] |[pic] |[pic] |
|objB.z |[pic] |[pic] |[pic] |

Exercise 2:
Given the following class hierarchy:

1. Create C++ code without attributes and methods for all for all 6 classes.

2. Extend the class character by a public attribute ch, so that it can store a single character.

3. Overload the operator + for the class Character, so that it can add two objects of type Character.

4. Override the operator + in the Digit class, so that it adds the numeric value of two digits and delivers the digit that we get if we finally apply “modulo 10”.
(Example ‘5’ + ‘6’ = ‘1’ // 5 + 6 = 11 % 10 = 1)

5. Extend the Object class by an object counter that counts the number of created objects for all objects of the above class hierarchy. (Tip: Lecture 9 slide 5) The counter should be embedded into the Object-class default constructor.

6. Change the visibility of the attribute ch, so that it is visible in all subclasses, but inaccessible from outside. Create a get-set method pair for the attribute ch.

7. Create a main-method, where you create 2 objects of each class in the above class hierarchy and that prints finally the value of your object counter (this should be 10).