CPP Object-Oriented Programming & Class Design

Question 1

What is encapsulation in C++?

Accepted Answer

Bundling data and related functions together

Answer

Encapsulation is a fundamental principle of Object-Oriented Programming (OOP) in C++. It involves binding data (attributes) and the methods (functions) that operate on that data into a single unit, typically a class. This mechanism hides the internal state of an object from the outside, exposing only necessary interfaces and protecting data integrity.

Question 2

What is the role of a constructor in a class?

Accepted Answer

Initializes an object upon creation

Answer

A constructor is a special member function of a class that is automatically called when an object of that class is created. Its primary role is to initialize the object's data members to a valid state, ensuring that the object is ready for use immediately after its instantiation. Constructors can also perform other setup tasks necessary for the object's proper functioning.

Question 3

What is inheritance in OOP?

Accepted Answer

Acquiring features from a base class

Answer

Inheritance is a fundamental OOP concept where a new class (derived class) acquires properties and behaviors (features) from an existing class (base class). This mechanism promotes code reusability and establishes an "is-a" relationship, allowing derived classes to extend or specialize the functionality of their base classes.

Question 4

What is polymorphism in C++?

Accepted Answer

Multiple meanings for the same interface

Answer

Polymorphism, meaning "many forms," allows objects of different classes to be treated as objects of a common base class through a unified interface. In C++, this is often achieved using virtual functions, enabling a single function call to invoke different implementations based on the actual type of the object at runtime, providing flexibility and extensibility.

Question 5

Which keyword is used to inherit a class?

Accepted Answer

:

Answer

In C++, the colon (:) symbol is used in the class declaration to specify inheritance. It is placed after the derived class name, followed by an access specifier (e.g., `public`, `protected`, `private`) and then the base class name, indicating that the derived class inherits from the specified base class.

(CPP) C++ Programming Professional Certificate Practice Test

(CPP) C++ Programming Professional Certificate Practice Test

CPP Object-Oriented Programming & Class Design