Question

There are many problems with the program below. Describe 5 of these problems in detail. For each, also explain how you could fix or avoid the issue.

#include <iostream>
using namespace std;

class Duck {
public:
    virtual void quack() {
        cout << "Quack" << endl;
    }
};

class RubberDuck : public Duck {
public:
    RubberDuck() {
        array = NULL;
    }

    RubberDuck(int size) {
        array = new int[size];
        array[0] = 1;
        array[1] = 2;
        array[2] = 3;
    }

    ~RubberDuck() {
        delete array;
    }

    void quack() {
        cout << "Squeak! ";
        for (int i = 0; i < arraySize; i++) {
            cout << array[0] << " ";
        }
        cout << endl;
    }

private:
    int* array;
    int arraySize;
};

int main() {
    Duck* rubberDuck;
    Duck& duck = *rubberDuck;

    duck.quack();

    delete[] rubberDuck;

    return 0;
}

Output when the code works:

Squeak! 1 2 3

Answer 1

Ans:-

1.

In constructor of RubberDuck must declare arraysize

Statement arraySize = size; should be added

2.

In array print statement in for loop i should be there in array[0] instead of 0 to print 1,2,3 values of array[0], array[1], array[2]

3. In destructor, array should be deleted as

delete[] array; instead of delete array;

4. Object of rubberDuck should be made

instead of Duck pointer

RubberDuck rubberDuck(3);

3 is arraySize

5. no need to use delete [] rubberDuck statement as it is not allocated dynamically.

#include <iostream>

using namespace std;

class Duck

{

public:

virtual void quack() {

cout << "Quack" << endl; } };

class RubberDuck : public Duck {

public: RubberDuck() {

array = NULL; }

RubberDuck(int size) {

array = new int[size];

array[0] = 1;

array[1] = 2;

array[2] = 3;

arraySize = size;}//initialise size

~RubberDuck() {

delete[] array; }//array use[]

void quack() {

cout << "Squeak! ";

for (int i = 0; i < arraySize; i++) { cout << array[i] << " "; } //i instead of 0

cout << endl; }

private:

int* array;

int arraySize; };

int main() {

//Duck *rubberDuck;

RubberDuck rubberDuck(3);//pass 3 to object

Duck& duck = rubberDuck;

duck.quack();

//delete duck; no need

return 0; }   

If any doubt ask in the comments