“C++ Interview Questions for Entry-Level Computer Science Students”


Are you an entry-level computer science student looking to learn the basics of C++ programming? If so, you’re in the right place. In this article, we’ll explore some fundamental C++ interview questions tailored to beginners. Whether you’re preparing for an interview or just starting your C++ journey, these questions and explanations will help you build a solid foundation.

1: What are the Different Data Types in C++?

   – C++ provides various data types, including primitive, derived, enumeration, and user-defined types. These include int, float, double, char, array, pointer, enum, and user-defined classes.

2: What is the Difference Between C and C++?

   – C is a procedural programming language, while C++ is an object-oriented programming language.

   – C++ supports data hiding through encapsulation, whereas C does not.

   – C++ is a superset of C, meaning that C++ includes all of C’s features and adds more, such as classes and objects.

3: What are Classes and Objects in C++?

   – In C++, a class is a user-defined data type that contains data members and member functions.

   – An object is an instance of a class, allowing you to work with the data and methods defined in that class.

4: What is the Difference Between Struct and Class?

   – In C++, a structure (struct) is similar to a class, but members are public by default.

   – A class has private members by default, which provides better encapsulation.

5: What is Operator Overloading in C++?

   – Operator overloading allows you to redefine the behavior of operators like +, -, *, /, etc. for user-defined data types.

   – For example, you can overload the ‘+’ operator to add two complex numbers.

6:- What is Polymorphism in C++?

   – Polymorphism means having many forms. It allows different behaviors in different situations.

   – C++ supports both compile-time and runtime polymorphism through function overloading and virtual functions.

7: Explain Constructors in C++.

   – Constructors are special member functions that are automatically called when an object is created.

   – Constructors have the same name as the class and initialize object attributes.

8: Tell Me About Virtual Functions.

   – A virtual function is a member function in the base class that you can override in a derived class.

   – It is declared using the `virtual` keyword and enables dynamic binding.

9: Compare Compile-Time and Runtime Polymorphism.

   – Compile-time polymorphism is resolved at compile time through function overloading.

   – Runtime polymorphism is determined at runtime using virtual functions and pointers.

10: What is a Friend Class and Friend Function in C++?

    – A friend class can access private, protected, and public members of other classes where it’s declared as a friend.

    – A friend function can access these members and is not a member function of the class.

11: What are the C++ Access Specifiers?

    – C++ has three access specifiers: public, protected, and private.

    – Public members are accessible from outside the class, protected members within the class and derived classes, and private members only within the class.

12: Define Inline Function.

    – An inline function is a function where the compiler places a copy of the code at each function call site.

    – It’s used to eliminate the function calling overhead for better performance.

13: What is a Reference in C++?

    – A reference is another name for an existing variable. Once initialized, it can be used interchangeably with the variable name.

    – Changes to a reference are reflected in the original variable.

14: Explain Abstraction in C++.

    – Abstraction is the concept of showing only essential details to the user while hiding irrelevant or internal information.

    – Classes and objects provide a way to implement abstraction in C++.

15: Is Destructor Overloading Possible? If Yes, Explain Why. If No, Explain Why Not.

    – Destructor overloading is not possible in C++. Destructors take no arguments, and there’s only one way to destroy an object.

16: What is Call by Value and Call by Reference?

    – Call by value involves passing a copy of the parameter to the function, and changes do not affect the original variable.

    – Call by reference passes the address of the variable, allowing changes to affect the original variable.

17: What is an Abstract Class, and When is It Used?

    – An abstract class cannot have instances and serves as a base for derived classes.

    – Abstract classes often contain pure virtual functions and are used for creating a common interface for derived classes.

18: What Are Destructors in C++?

    – A destructor is a special member function that is automatically called when an object is destroyed.

    – It is used to clean up resources associated with the object.

19: What Are Static Members and Static Member Functions?

    – Static members belong to the class, not to instances of the class. They are shared among all objects.

    – Static member functions can be called using the class name and do not operate on instance-specific data.

20: Explain Inheritance.

    – Inheritance allows you to create new classes (derived) from existing classes (base).

    – Derived classes inherit the attributes and methods of the base class, promoting code reuse.


These C++ interview questions are a great starting point for entry-level computer science students looking to grasp the basics of C++. Understanding these concepts will not only help you succeed in interviews but also lay the foundation for your C++ programming journey. As you progress, consider exploring more advanced topics and real-world applications to deepen your knowledge. Happy coding!

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