Abstraction Interview Questions Mock Test

Question 1: C++ OOPS Abstraction Concept

What is the main purpose of abstraction in C++?

Question 2: C++ OOPS Abstract Class

Which keyword is used to declare a pure virtual function in C++?

Question 3: C++ OOPS Interface through Abstract Class

How can abstraction be achieved in C++?

Question 4: C++ OOPS Pure Virtual Function Example

What will be the output of the following code?

#include <iostream>
using namespace std;
class Shape {
public:
    virtual void draw() = 0;
};
class Circle : public Shape {
public:
    void draw() { cout << "Drawing Circle"; }
};
int main() {
    Circle c;
    c.draw();
}

Question 5: C++ OOPS Abstract Class Instantiation

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

Question 6: C++ OOPS Abstraction with Multiple Derived Classes

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();
}

Question 7: C++ OOPS Partial Abstraction

Can an abstract class in C++ have normal (non-virtual) functions?

Question 8: C++ OOPS Pure Virtual Function Without Definition

Which of the following is true about pure virtual functions?

Question 9: C++ OOPS Abstract Class Pointer

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();
}

Question 10: C++ OOPS Real-life Example of Abstraction

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