Object-Oriented Programming Interview Questions

Object Oriented Programming Interview Questions

Object Oriented Programming (OOP) is a popular programming pattern that has been widely adopted by developers across industries. In addition, OOP allows developers to create modular, reusable, and scalable code by organizing data and behavior into objects.

In this blog, we will discuss the basics of OOP, its importance in the industry, and what it is used for. We will also take a look at the job outlook for OOP in 2023 and provide tips on how to crack an OOP interview in the coming year. Additionally, we will provide a list of 10+ best Object Oriented Programming interview questions for practice in 2023.

Moreover, if you are an experienced developer or fresher in this field, this blog will provide valuable information about Object Oriented Programming and help you prepare for your next interview.

Are you struggling with the complex concepts of object-oriented programming languages? Do not worry anymore our programming experts are here to provide you with high-quality solutions in various languages such as Python programming help, javascript assignment help and many other languages.

Let’s discuss object-oriented concepts in detail.

What Is Object Oriented Programming?

  • Object-oriented programming (OOP) is a fundamental programming pattern that is mainly used in software development. 
  • It includes creating objects that have properties and methods that can be used to interact with other objects in the program. 
  • Moreover, OOP is commonly used in languages such as Java, C++, and Python

What Is Object-Oriented Programming Used For?

  • Object-oriented programming is important because it helps developers organize and structure their code to make it easier to manage and reuse.
  • With OOP, code is broken down into objects with their own properties and methods. 
  • In addition, these objects can interact with each other and making it possible to build complex programs without having to write a lot of repetitive code.

Why Is Object Oriented Programming Important? 

Here are some points on why is object-oriented programming important : 

1. Helps In Making Modules

OOP makes it possible to break code down into smaller, reusable pieces or modules. This can help reduce development time and make it easier to maintain and update code over time.

2. Encapsulation

OOP allows developers to hide the complexity of code behind a simple interface. This means that other developers can use the code without understanding how it works under the hood.

3. Simplify The Code

OOP allows developers to focus on the important details of a program and ignore the rest. This can help simplify code and make it easier to understand and modify.

4. Allows To Reuse Code

OOP allows developers to reuse code by inheriting properties and methods from existing objects. This can help reduce code duplication and improve code efficiency.

Job Outlook For Object-Oriented Programming in 2023 

According to Payscale USA, the average salary for a software developer with OOP skills is $80,643 annually. The job outlook for software developers is estimated to grow by 21% from 2019 to 2029, which is much faster than the average for all occupations.

In recent years, there has been a growing demand for software developers with OOP skills, particularly in industries such as finance, healthcare, and technology. Furthermore, this trend is expected to continue in the coming years as more companies embrace digital transformation and rely on software solutions to improve their operations.

Here are some jobs that an object-oriented skilled person can do : 

Job Title Salary Range Average Salary 
Software Development Engineer$82k – $149k$116,145
Software Engineer$66k – $128k$85,476
Software Developer$52k – $113k$71,747
Senior Software Engineer$91k – $168k$121,083
iOS Developer$61k – $131k$77,638
SAP ABAP Programmer$48k – $135k$113,906
Video Game Designer$40k – $88k$65,137

Tips To Crack The Object Oriented Programming Interview Questions In 2023

Here are a few tips that students should follow to crack object-oriented programming : 

1. Brush Up On Basic OOP Concepts

Ensure you have a solid understanding of the basic concepts of OOP, such as encapsulation, inheritance, and polymorphism. Be able to explain these concepts in simple terms and provide examples of their use.

2. Practice Coding

OOP interviews often involve coding exercises, so practice writing OOP code in your preferred language. This will help you gain confidence in your coding abilities and identify areas where you need to improve.

3. Review Design Principles

Review key OOP design principles such as SOLID and DRY. Understand how these principles apply to real-world problems and be able to explain them.

4. Understand Data Structures And Algorithms

OOP is often used in conjunction with data structures and algorithms, so ensure you have a good understanding of these topics. Be able to identify the best data structure and algorithm to solve a given problem.

5. Prepare For Behavioral Questions

In addition to technical questions, OOP interviews may include behavioral questions to assess your problem-solving skills and ability to work in a team. Be prepared to provide examples of how you have solved problems in the past and how you work with others.

7. Stay Up-To-Date

Keep up-to-date with the latest trends and developments in OOP. Attend conferences, read blogs, and follow experts on social media to stay informed.

Also read: pay someone to do my java homework and assignment

10+ Common Object-Oriented Programming Interview Questions For Practice In 2023

Here are some recently asked  questions that freshers and experienced must practice before the interview: 

1. What is Object-Oriented Programming (OOP)?

Object-Oriented Programming (OOP) is a method of programming that represents and manipulates data using objects. It is based on the idea of objects, which can contain data and the code necessary to manipulate that data.

2. What are the four main principles of OOP?

The four main principles of OOP are:

  • Encapsulation
  • Abstraction
  • Inheritance
  • Polymorphism

3. What is the difference between an object and a class in OOP?

A class is a blueprint or template for creating objects, while an object is an example of a class. A class defines the properties and methods of an object, while an object is an instance of a class with its own state and behavior.

4. What is inheritance in OOP? How does it work?

Inheritance is a mechanism in OOP by which a new class is created from an existing class, inheriting its properties and methods. The new class is called the derived class or subclass, while the existing class is called the base class or superclass. Inheritance allows the code to be reused, promoting the reuse of existing code and reducing the development time.

5. What is encapsulation in OOP?

Encapsulation is the idea of wrapping data and behavior into a single unit (class) to hide the implementation details from the user. It is one of the four main principles of OOP and promotes the concept of data hiding.

6. What is polymorphism in OOP?

Polymorphism is the ability of an object to take on many forms or shapes, depending on the context in which it is used. It allows objects of different classes to be treated as if they are of the same class, promoting code reuse and flexibility.

7. What is the distinction between abstraction and encapsulation?

Abstraction is the process of making complicated systems easier to understand by breaking them up into smaller, easier-to-handle parts. At the same time, encapsulation is the idea of wrapping data and behavior into a single unit (class) to hide the implementation details from the user. While both concepts promote the idea of data hiding, abstraction focuses on simplifying the system, while encapsulation focuses on hiding the implementation details.

8. What is a constructor in OOP?

A class’s constructor is a special method used to set up new objects of that class. It is called automatically when an object is created and can be used to set initial values for its properties.

9. What is method overloading in OOP?

Object-Oriented Programming (OOP) lets a class have more than one method with the same name but different parameters. This is called method overloading. When a method is called, the compiler determines which version of the method to call based on the parameters passed to it.

10. What is method overriding in OOP?

Method overriding is a feature in OOP that allows a subclass to implement a method already defined in its superclass. The name, return type, and parameters of the method in the subclass must be the same as those of the method in the superclass.

11. What is the distinction between an abstract class and an interface?

An abstract class is a class that cannot be created, and other classes use it as a starting point. It can have abstract methods and methods that are not abstract. It can also have fields and constructors.


In the end, object-oriented programming is an essential aspect of modern software development. It allows developers to write modular and maintainable code that can easily be reused in different parts of an application. Moreover, OOP allows developers to create complex applications easily and provides a better way of representing real-world objects.

In this blog, we have covered OOP’s basic concepts and principles, including encapsulation, inheritance, polymorphism, and SOLID design principles. We have also provided tips on preparing for an OOP interview in 2023. You must follow these tips and be able to crack the interview. In addition, we also discussed the job outlook of jobs related to OOP.  All the best for your object-oriented programming interview.