C++ OOPs Concepts Test 5

Which of the following initializes an object car of class Car with a constructor taking two arguments?

What is the order of execution for constructors and destructors in nested objects?

Why does encapsulation improve security?

If a member is declared protected in the base class, how is it inherited in a public derived class?

What will this print?

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

What will be the output?

#include <iostream>
using namespace std;
class Base {
public:
    virtual void show() = 0;
};
class Derived : public Base {
public:
    void show() { cout << "Derived"; }
};
int main() {
    Base* b = new Derived();
    b->show();
}

What will be the output?

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

Which of the following is the correct way to access a static variable of a class `Sample` named `count`?

Which statement about overloading [] is correct?

How does adding virtual functions affect object size?

When is a destructor of a class called automatically?

When is a destructor called for an automatic (stack) object?

Which of the following is a real-world analogy for encapsulation?

What will the following code output?

#include<iostream>
using namespace std;
class Base {
public:
    void show() { cout << "Base"; }
};
class Derived : public Base {
public:
    void show() { cout << "Derived"; }
};
int main() {
    Derived d;
    d.show();
}

What is the output?

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

Which is the best real-life example of abstraction in C++?

Which of the following is NOT true about friend functions in C++?

What will be the output?

#include <iostream>
using namespace std;
class Alpha {
    static int x;
    int y;
public:
    Alpha() { y = 5; }
    static void printX() { cout << x; }
    void printY() { cout << y; }
};
int Alpha::x = 100;
int main() {
    Alpha::printX();
    Alpha a;
    a.printY();
}

What will be the output?

#include <iostream>
using namespace std;
class Point {
    int x;
public:
    Point(int v) : x(v) {}
    Point operator-(Point p) { return Point(x - p.x); }
    void show() { cout << x; }
};
int main() {
    Point p1(10), p2(3);
    Point p3 = p1 - p2;
    p3.show();
}

What will be the output?

#include <iostream>
using namespace std;
class A { public: virtual void f() { cout << "A"; } };
class B : public A { public: void f() { cout << "B"; } };
class C : public B { public: void f() { cout << "C"; } };
int main() {
    A* p = new C();
    p->f();
}