C++ OOPs Concepts Test 3

Which operator is used to access class members via an object?

Which of the following correctly declares a copy constructor for class `Student`?

What will happen if you try to directly access a private data member of a class?

What will the following program print?

#include<iostream>
using namespace std;
class A {
public: void display() { cout << "A "; }
};
class B : public A {
public: void displayB() { cout << "B "; }
};
class C : public B {
public: void displayC() { cout << "C"; }
};
int main() {
    C obj;
    obj.display();
    obj.displayB();
    obj.displayC();
}

What will this code print?

#include<iostream>
using namespace std;
class Base {
public: virtual void show() { cout << "Base"; } };
class Derived : public Base {
public: void show() { cout << "Derived"; } };
int main() {
    Base* b = new Derived();
    b->show();
}

What happens if you try to instantiate an abstract class in C++?

What will be the output?

#include <iostream>
using namespace std;
class A {
    int x = 5;
    friend class B;
};
class B {
public:
    void show(A a) { cout << a.x; }
};
int main() {
    A a;
    B b;
    b.show(a);
}

How can a static member function be called?

What will be the output?

#include <iostream>
using namespace std;
class Complex {
    int x;
public:
    Complex(int v) : x(v) {}
    friend Complex operator+(Complex c1, Complex c2);
    void show() { cout << x; }
};
Complex operator+(Complex c1, Complex c2) {
    return Complex(c1.x + c2.x);
}
int main() {
    Complex a(3), b(4);
    Complex c = a + b;
    c.show();
}

Which statement is true about pure virtual functions?

If Student *ptr; is a pointer to a Student object, how can we call its function show()?

When does the compiler provide a default copy constructor?

How is encapsulation different from abstraction?

The "diamond problem" occurs in which type of inheritance?

What happens if `virtual` is removed in the above code?

What will be the output of this code?

#include <iostream>
using namespace std;
class Animal {
public:
    virtual void sound() = 0;
};
class Dog : public Animal {
public:
    void sound() { cout << "Bark"; }
};
class Cat : public Animal {
public:
    void sound() { cout << "Meow"; }
};
int main() {
    Animal* a = new Dog();
    a->sound();
}

Which statement is true about friend classes in C++?

What happens to static members when all objects of the class are destroyed?

Which of the following statements is NOT true?

What is the V-Table in C++?