C# (CSharp) and .NET Interview Questions with Answers

If you are looking to clear C# and .NET Interviews then you have landed at the right course. You can be a hero in your project/company , you must have handled complex scenarios.

But failing to answer simple .NET , C# Fundamental question can lead to a very negative impact during interviews.

This course focuses on Fundamental questions around C# and .NET… Happy job hunting.

Below is the list of C# interview questions covered in the Series.

Question 1 :– Explain difference between .NET and C# ?
Question 2 :– .NET Framework vs .NET Core vs .NET 5.0
Question 3 :– What is IL ( Intermediate Language) Code ?
Question 4 :– What is the use of JIT ( Just in time compiler) ?
Question 5 :– Is it possible to view IL code ?
Question 6 :– What is the benefit of compiling in to IL code ?
Question 7 :– Does .NET support multiple programming languages ?
Question 8 :– What is CLR ( Common Language Runtime) ?
Question 9 :– What is managed and unmanaged code ?
Question 10 :– Explain the importance of Garbage collector ?
Question 11 :– Can garbage collector claim unmanaged objects ?
Question 12 :– What is the importance of CTS ?
Question 13 :– Explain CLS ?
Question 14 :– Difference between Stack vs Heap ?
Question 15 :– What are Value types & Reference types?
Question 16 :– Explain boxing and unboxing ?
Question 17 :– What is consequence of boxing and unboxing ?
Question 18 :– Explain casting, implicit casting and explicit casting ?
Question 19 :– What can happen during explicit casting ?
Question 20 :– Differentiate between Array and ArrayList ?
Question 21 :– Whose performance is better array or arraylist ?
Question 22 :– What are generic collections ?
Question 23 :– What are threads (Multithreading)?
Question 24 :– How are threads different from TPL ?
Question 25 :– How do we handle exceptions in C#(try/catch)?
Question 26 :– What is the need of finally?
Question 27 :– Why do we need the out keyword ?
Question 28 :– What is the need of Delegates ?
Question 29 :– What are events ?
Question 30 :– What’s the difference between Abstract class and interface ?
Question 31  :– What is a delegate and How to create a delegate ?
Question 32  :– Where have you used delegates ?
Question 33  :– What is a Multicast delegates ?
Question 34  :– What is a Event ?
Question 35  :– How to create a event ?
Question 36  :– Delegate vs Events.
Question 37 :– Why do we need OOP ?
Question 38 :– What are the important pillars of OOPs ?
Question 39 :– What is a class and object ?
Question 40 :– Abstraction vs Encapsulation?
Question 41 :– Explain Inheritance ?
Question 42 :– Explain virtual keyword ?
Question 43 :– What is overriding ?
Question 44 :– Explain overloading ?
Question 45 :– Overloading vs Overriding ?
Question 44 :– What is polymorphism ?
Question 45 :– Can polymorphism work with out inheritance ?
Question 46 :– Explain static vs dynamic polymorphism ?
Question 47 :– Explain operator overloading ?
Question 48  :– Why do we need Abstract classes ?
Question 49  :– Are Abstract methods virtual ?
Question 50  :– Can we create a instance of Abstract classes ?
Question 51  :– Is it compulsory to implement Abstract methods ?
Question 52  :– Why simple base class replace Abstract class ?
Question 53  :– Explain interfaces and why do we need it ?
Question 54  :– Can we write logic in interface ?
Question 55  :– Can we define methods as private in interface ?
Question 56  :– If i want to change interface what’s the best practice ?
Question 57  :– Explain Multiple inheritance in Interface ?
Question 58  :– Explain Interface Segregation principle ?
Question 59  :– Can we create instance of interface ?
Question 60  :– Can we do Multiple inheritance with Abstract classes ?
Question 61 :– Difference between Abstract Class & Interfaces?
Question 62  :– Why do we need constructors ?
Question 63  :– In parent child which constructor fires first ?
Question 64  :– How are initializers executed ?
Question 65  :– How are static constructors executed in Parent child ?
Question 66  :– When does static constructor fires ?
Question 70 :– What is Shadowing?
Question 71 :– Explain method hiding?
Question 72 :– Shadowing vs Overriding ?
Question 73 :– When do we need Shadowing ?
Question 74 :– Explain Sealed Classes ?
Question 75 :– Can we create instance of sealed classes ?
Question 76 :– What are nested classes and when to use them ?
Question 77 :– Can Nested class access outer class variables ?
Question 78 :– Can we have public, protected access modifiers in nested class ?
Question 79 :– Explain Partial classes ?
Question 80 :– In What scenarios do we use partial classes ?
Question 81 :– What is SOLID ?
Question 82 :– What is the full form of SOLID ?
Question 83 :– What is the goal of SOLID ?
Question 84 :– Explain SRP with A example ?
Question 85 :– What is the benefit of SRP ?
Question 86 :– Explain OCP with a example ?
Question 87 :– What is the  benefit of OCP ?
Question 88 :– Can you explain LISKOV Principle and it’s violation?
Question 89 :– How can we fix LISKOV Problem ?
Question 90 :– Explain Interface Segregation Principle ?
Question 91 :– Is there a connection between LISKOV and ISP ?
Question 92 :– Define dependency inversion ?
Question 93 :– What is higher level module and lower level module ?
Question 94 :– How does dependency inversion benefit, show with an example ?
Question 95 :– Will only Dependency inversion solve decoupling problem ?
Question 96 :– Why do developers  move object creation outside high lever module ?
Question 97 :– Explain IOC ( Inversion of Control) ?
Question 98 :– Explain Dependency Injection with an example ?
Question 99 :– Is SOLID, IOC and DI design pattern or Principle?
Question 100 :– Is only SOLID Enough for good code/ architecture ?