Thread by @swapnakpanda

OOPs & Design Patterns Interview Questions

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Disclaimer:

• The questions covered here are mostly conceptual
• I never claim only these type of questions are/should be asked during interviews
• For interviews, you should have fundamentals strong. And you should be able to provide solutions to practical problems.

Series: 1️⃣
Level: Beginner/Medium
Topic:

1️⃣ OOPs Basics
2️⃣ Class, Object, Interface
3️⃣ Encapsulation, Abstraction, Polymorphism, Inheritance
4️⃣ Constructor and Destructor
5️⃣ Design Patterns

1️⃣ OOPs Basics

✪ What is a programming paradigm?
✪ Mention various programming paradigm types.
✪ What is structured programming?
✪ What is OOPs?
✪ Why is OOPs needed?/Advantages of OOPs
✪ Where should OOPs not be used?
✪ What are major features of OOPs?

✪ Mention few popular languages that support OOPs.
✪ Does <your_language> support OOPs? How?

2️⃣ Class, Object, Interface

✪ Define a class.
✪ What is an Object?
✪ Does class take memory?
✪ What does a class provide/define?
✪ What is a property in a class?
✪ What is a method in a class?
✪ What is an abstract method?
✪ What is an abstract class?

✪ What is an Interface?
✪ What does "static" mean wrt Properties and Methods?

3️⃣ Encapsulation, Abstraction, Polymorphism, Inheritance

✪ What is encapsulation?
✪ What is Data Hiding?
✪ What is Data Binding?
✪ How does <your_language> do encapsulation?
✪ What is abstraction?
✪ How is abstraction accomplished?

✪ What is Inheritance?
✪ Give an example of Inheritance
✪ What are advantages of Inheritance?
✪ Are there any limitations of Inheritance?
✪ What are different types of Inheritance?
✪ Which type of inheritance does <your_language> support?
✪ What is a super class/sub class?

✪ What is polymorphism?
✪ What are different types of polymorphism? Explain.
✪ What is Method Overloading?
✪ What is Method Overriding?
✪ Tell the difference between Overloading and Overriding.
✪ How does <your_language> support overloading and overriding?

4️⃣ Constructor and Destructor

✪ What is a constructor?
✪ What are different types of constructor?
✪ What do you mean by a default constructor?
✪ What is a parameterised constructor?
✪ What is a copy constructor?
✪ When is a constructor invoked?

✪ Is a parent class constructor invoked when a child class constructor is invoked? In which order?
✪ Is creation of an object mandatory? If no, when?
✪ Can an interface have a constructor?
✪ What is a destructor?
✪ When is a destructor invoked?

✪ Is destructor invoked automatically or manually?
✪ Does <your_language> support defining a destructor?
✪ In which order destructors are invoked in case of inheritance?
✪ What is garbage collection?
✪ How does <your_language> do garbage collection?

5️⃣ Design Patterns

✪ What is a design pattern?
✪ What is GoF?
✪ Mention categories in which all design patterns are classified.
✪ What do you mean by creational design pattern?
✪ Define all creational design patterns.
✪ What do you mean by structural design pattern?

✪ Define all structural design patterns.
✪ What do you mean by behavioural design pattern?
✪ Define all behavioural design patterns.
✪ What do you mean by Singleton?
✪ Why is singleton necessary?
✪ Doesn't Singleton break the purpose of OOPs?
✪ What is a Facade?

✪ What is a Factory?
✪ What is a Builder?
✪ What is a composite?
✪ How is composite different from inheritance?
✪ What is an adapter? Give some example.
✪ What is a decorator? Give some example.
✪ What is a Proxy?
✪ Explain different type of proxies.

✪ What is chain of responsibility?
✪ What is a bridge?
✪ Difference between a bridge and adapter?
✪ What is service locator design pattern?
✪ What is dependency injection?
✪ Difference between Service Locator and Dependency Injection
✪ What is MVC?

✪ What is a DAO?
✪ What is a DTO?
✪ Define the strategy to describe a design pattern.

The next 🧵 of this series will provide questions from

1️⃣ Class/Interface Design
2️⃣ More on OOPs
3️⃣ More on Design Patterns

Find "Interview Questions" that I post for few other subjects, 👇

https://twitter.com/swapnakpanda/status/1456599023704436744?s=20