Nailing Object-Oriented Programming Interviews: Common Questions

Object-oriented programming is significant in interviews and you need to have a deeper understanding of the topic to help you prepare for oops interview questions. This article on oops interview questions can assist you in answering frequently asked oops interview questions.

OOPs interview questions and answers


Object-Oriented Programming, or OOP, offers a structured software design approach, modeling real-world entities as encapsulated objects. Inheritance, polymorphism, encapsulation, and abstraction manage complexity in extensive codebases. The interview prep must cater accordingly since it assesses candidates' problem-solving and design skills. Common questions for Object-Oriented Programming Interviews focus on explaining the four pillars: encapsulation, inheritance, abstraction, and polymorphism. Evaluations of solid principles and design patterns assess the capacity to create scalable, maintainable software structures. The OOP concepts, explained here make coding patterns feel like building with LEGO bricks.

Common Questions for Object-Oriented Programming Interviews

What are Classes and Objects?

Think of classes as blueprints. They help us create objects that are like real-world things in our coding patterns. A class holds information (attributes) and actions (methods) related to these objects. It's like a template for creating and organizing stuff in our code. Objects are the actual stuff made from those blueprints (classes). They have qualities called attributes that describe them. Imagine an object as a thing and its attributes as facts about that thing. These OOP concepts let us make many of these things easily.

What is Inheritance?

Inheritance lets us create new things based on existing ones, like building on top of something. It's like using blueprints to make new things quickly and neatly. Think of these OOP concepts as using one plan (single inheritance), multiple plans (multiple inheritance), or even a chain of plans (multilevel inheritance) to create things in the best way possible.

What is Encapsulation?

Encapsulation is like putting things in a safe box. These OOP concepts are about packing data and its actions together in a class. This keeps data protected from unwanted changes. Only specific actions can touch the data, making programs safer and clearer. Encapsulation keeps data hidden, making it simpler to manage code.

What is Polymorphism?

Polymorphism means one thing can take many forms. It's like using the same method for different things as OOP concepts. This flexibility helps us write less repetitive code and makes our programs adaptable. Two ways to see polymorphism are method overloading and method overriding. Method overloading means using the same method name but giving it different jobs based on what the coding patterns give it. Method overriding happens when a new class changes how an inherited method works. These tricks let us use our methods in clever ways.

How does Procedural programming differ from OOPs?

Procedural programming relies on functions, while OOP uses objects to represent real-world entities.

Could you explain the various types of constructors?

Types of constructors include Default, Parameterized, Copy, Private, and Static constructors.

Can you highlight the distinctions between a class and a structure?

A class defines a blueprint for objects, while a structure groups variables of different data types under one heading.

Could you define the concept of a superclass in object-oriented programming?

A superclass is a parent class from which a subclass inherits coding patterns and methods.

Could you provide a comparison between method overloading and method overriding?

Overloading involves using the same method name with different parameters, while overriding modifies a method in a subclass inherited from a superclass.

What is the significance of Coupling in OOP, and how does it contribute to software design?

Coupling refers to the degree of dependency between software components; proper coupling enhances maintainability and reusability.

What defining characteristics can be attributed to an abstract class?

An abstract class has at least one abstract method, cannot be instantiated, and can have both abstract and non-abstract methods.

How does constructor chaining work in object-oriented programming?

Constructor chaining is a mechanism in which one constructor calls another within the same class hierarchy.

Strategies for Excelling in Object-Oriented Programming Interviews

Study Core Concepts Thoroughly for Interview Prep

  • Master the coding patterns of confident explanations.
  • Dive into coding patterns and principles to impress.

Interview Prep with Coding Exercises

  • Solve puzzles that are available online.
  • Create small projects to apply coding patterns.

Interview Prep with Behavioral Questions

  • Explain OOP concepts with relatable examples.
  • Share past projects to show practical understanding.

Interview Prep with Mock Interviews and Peer Discussions

  • Practice mock interviews with peers or mentors.
  • Join group discussions on OOP concepts to solidify knowledge.

Real-Life Examples and Case Studies for Object-Oriented Programming Interviews

Designing a Banking System as Interview Prep

Picture creating a strong banking system. OOP concepts help by breaking it into classes—accounts, transactions, and users. Each class handles its data and coding patterns, just like real-world banking parts. Inheritance links classes, like various accounts inheriting from a main account class. Encapsulation secures data. OOP builds an organized, secure banking system for modern finance.

Building a Media Streaming Service as Interview Prep

The OOP concepts fit perfectly when crafting a media streaming service with music, movies, and shows. Class hierarchy creates a base class for all content, extended to special classes like Music, movies, TVShow. Polymorphism shines by allowing smooth content switching. Different types share an interface. The coding patterns craft a flexible, user-friendly streaming service.


Core ideas such as classes, objects, inheritance, encapsulation, and polymorphism work together to create flexible software systems. Common Object-Oriented Programming Interviews feature questions on various topics. To excel in interview prep, it's vital to understand key concepts thoroughly by enrolling in a software developer course, applying them through coding exercises and projects, explaining them with relatable examples, and practicing through mock interviews and discussions with peers. Real-life instances, like designing a banking system or a media streaming service, illustrate how OOP principles can be used practically.


Why is OOP important in interviews?

OOP concepts are frequently assessed in coding interviews as they demonstrate a candidate's ability to design and organize code effectively.

How does encapsulation promote data hiding?

Encapsulation restricts access to certain attributes, allowing controlled interaction and preventing unintended manipulation.

Explain method overloading and method overriding.

Method overloading involves creating multiple methods with the same name but different parameter lists, while method overriding provides a new implementation for a method inherited from a superclass.

How does polymorphism relate to method overriding?

Polymorphism allows a subclass to provide a specific implementation for a method inherited from its superclass, enabling dynamic method binding.

How do you handle exceptions in OOP?

Exceptions are typically handled using try-catch blocks, allowing code to handle unexpected errors during execution gracefully.