25 Common C# Interview Questions for Freshers: A Comprehensive Guide

If you’re a fresher looking to start your career in C#, it’s important to prepare yourself for the interviews. In this blog post, we’ll discuss some common C# interview questions for freshers that can help you showcase your knowledge and skills.

Let’s briefly discuss each of these questions:

  1. What is C#? 

    C# is a modern, object-oriented programming language that is widely used to build various types of applications, including desktop, web, and mobile applications.

  2. What is the difference between C# and .NET?

    C# is a programming language, while .NET is a software development framework. C# is used to write code in .NET, which includes libraries, tools, and runtime components.

  3. What is the difference between value types and reference types in C#?

    Value types store data directly in memory, while reference types store a reference to the data in memory.

  4. What is a constructor?

    A constructor is a special method that is used to create an object of a class. It is called automatically when an object is created.

  5. What is an interface in C#?

    An interface is a blueprint for a group of related methods, properties, and events. It defines the contract that a class must implement.

  6. What is the difference between abstract classes and interfaces?

    An abstract class can have both abstract and non-abstract members, while an interface can only have abstract members. A class can implement multiple interfaces, but it can inherit only one abstract class.

  7. What is a delegate in C#?

    A delegate is a type that represents a method signature. It is used to pass methods as arguments to other methods.

  8. What is a lambda expression?

    A lambda expression is a shorthand way of defining a method. It is used to create anonymous methods that can be passed as arguments to other methods.

  9. What is a generic in C#?

    A generic is a way to create a class, method, or interface that can work with any data type. It allows you to write reusable code that is type-safe.

  10. What is a collection in C#?

    A collection is a group of related objects. It is used to store and manipulate data in a structured way.

  11. What is the difference between List and Array?

    List is a dynamic collection that can grow or shrink in size, while an array is a fixed-size collection. List also provides more functionality than an array, such as the ability to add, remove, and sort elements.

  12. What is LINQ?

    LINQ stands for Language Integrated Query. It is a set of language extensions in C# that allow you to query and manipulate data from different sources, such as databases, collections, and XML documents.

  13. What is Entity Framework?

    Entity Framework is an Object-Relational Mapping (ORM) framework in .NET. It provides a way to work with databases using C# objects, making it easier to create and maintain database applications.

  14. What is a virtual method in C#?

    A virtual method is a method that can be overridden in a derived class. It allows you to provide a default implementation in the base class and customize it in the derived classes.

  15. What is a sealed class in C#?

    A sealed class is a class that cannot be inherited. It is used to prevent further modification of the class or to ensure that a specific implementation is used.

  16. What is an extension method in C#?

    An extension method is a method that extends the functionality of an existing class without modifying it. It allows you to add new methods to a class without having to create a new derived class.

  17. What is a static class in C#?

    A static class is a class that contains only static members. It cannot be instantiated, and all its members can be accessed using the class name.

  18. What is boxing and unboxing in C#?

    Boxing is the process of converting a value type to a reference type, while unboxing is the process of converting a reference type back to a value type. It can have performance implications and should be used with care.

  19. What is an exception in C#?

    An exception is a runtime error that occurs when a program encounters an unexpected condition. It can be caught and handled using the try-catch block.

  20. What is the difference between throw and throw ex in C#?

    Throw ex rethrows an exception and changes the call stack, while throw simply throws the exception without modifying the call stack.

  21. What is a try-catch block in C#?

    A try-catch block is used to catch and handle exceptions in C#. It consists of a try block, where the code that can cause an exception is written, and a catch block, where the exception is caught and handled.

  22. What is a finally block in C#?

    A finally block is used to execute code that should always be executed, regardless of whether an exception is thrown or not.

  23. What is a namespace in C#?

    A namespace is a way to organize code in C#. It allows you to group related classes, interfaces, and other types in a logical and hierarchical way.

  24. What is a using statement in C#?

    A using statement is used to ensure that an object is properly disposed of after it is no longer needed. It is often used with classes that implement the IDisposable interface.

    Try our beginner friendly C# online quiz.

  25. What is the difference between stack and heap memory in C#?

    Stack memory is used for local variables and method calls, while heap memory is used for dynamic memory allocation. Stack memory is automatically managed by the runtime, while heap memory must be explicitly allocated and deallocated using the new and delete operators.


In conclusion, preparing for a C# interview as a fresher can be overwhelming, but having a good understanding of the language basics, object-oriented concepts, and commonly used frameworks and tools such as LINQ, Entity Framework, and Visual Studio can greatly increase your chances of success. By reviewing and practicing these 25 questions, you can gain a solid foundation in C# and feel more confident during your interview. Good luck!

Don’t forget to check out this Udemy course: Master C# And SQL By Building Applications

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