60 Common C# Interview Questions in 2022: Ace Your Next Interview

Administration / 4 Dec, 2022

60 Common C# Interview Questions in 2022: Ace Your Next Interview

Note: While the year 2022 has passed, these questions remain relevant and can still help you prepare for your C# interview.

Core C# Concepts

1. What is the difference between value and reference types in C#?
2. Explain the concept of garbage collection in C#.
3. What is the purpose of the using statement in C#?
4. What are delegates and events in C#?
5. Explain the concept of polymorphism in C#.
6. What is the difference between abstract and virtual methods?
7. What are interfaces in C#?
8. What is the difference between struct and class in C#?
9. Explain the concept of boxing and unboxing.
10. What is the difference between const and readonly modifiers?

Data Structures and Algorithms

1. Implement a linked list in C#.
2. What is the difference between a stack and a queue?
3. Implement a binary search tree in C#.
4. What is the time complexity of a bubble sort algorithm?
5. What is the difference between recursion and iteration?

LINQ

1. What is LINQ?
2. Explain the difference between deferred execution and immediate execution in LINQ.
3. Write a LINQ query to filter a list of numbers based on a condition.
4. What is the purpose of the join operator in LINQ?
5. How can you use LINQ to group a list of objects?

.NET Framework

1. What is the Common Language Runtime (CLR)?
2. What is the difference between the .NET Framework and .NET Core?
3. What is the purpose of the AppDomain class?
4. What is the difference between System.Object and System.ValueType?
5. What is the purpose of the Assembly class?

C# Advanced Topics

1. Explain the concept of asynchronous programming in C#.
2. What is the purpose of the async and await keywords?
3. What is reflection in C#?
4. What is a lambda expression?
5. Explain the concept of dependency injection.

Design Patterns

1. What is the Singleton pattern?
2. What is the Factory pattern?
3. What is the Observer pattern?
4. What is the Decorator pattern?
5. What is the Strategy pattern?

.NET Core

1. What are the key differences between .NET Framework and .NET Core?
2. What is ASP.NET Core?
3. What is Entity Framework Core?
4. What is gRPC?
5. What is Blazor?

C# Best Practices

1. What are some best practices for writing clean and maintainable C# code?
2. How can you improve the performance of your C# applications?
3. What are some common C# coding mistakes to avoid?
4. How can you write unit tests for your C# code?
5. What is code refactoring?

Interview Tips

1. How can you prepare for a C# interview?
2. What questions should you ask the interviewer?
3. How can you handle a difficult interview question?
4. How can you follow up after an interview?
5. What are some common C# interview mistakes to avoid?

Additional Questions (Depending on Experience Level)

1. What is your experience with multithreading and concurrency in C#?
2. What is your experience with design patterns in C#?
3. What is your experience with cloud platforms like Azure or AWS?
4. What is your experience with microservices architecture?
5. What is your experience with testing frameworks like NUnit or xUnit?

Additional Questions (Based on Job Role)

1. For a web developer: What is your experience with ASP.NET Core and web APIs?
2. For a data scientist: What is your experience with data structures and algorithms for data analysis?
3. For a game developer: What is your experience with Unity or Unreal Engine?
4. For a mobile developer: What is your experience with Xamarin or .NET MAUI?
5. For a backend developer: What is your experience with database technologies and cloud infrastructure?

By practicing these questions and understanding the underlying concepts, you can significantly improve your chances of success in your next C# interview.