Top 100+ Advanced dot net and C# Interview Questions for 2024

 In this blog post, we will dive into the top 100+ advanced dot net and C# interview questions for 2024. Whether you’re a seasoned developer looking to level up your skills or a newcomer aiming to land your dream job, mastering these questions will set you apart from the competition.

Basic Dot Net and C# Question:-

1. Explain difference between .NET and C# ?
2. .NET Framework vs .NET Core vs .NET 5.0
3. What is IL ( Intermediate Language) Code ?
4. What is the use of JIT ( Just in time compiler) ?
5. Is it possible to view IL code ?
6. What is the benefit of compiling in to IL code ?
7. Does .NET support multiple programming languages ?
8. What is CLR ( Common Language Runtime) ?
9. What is managed and unmanaged code ?
10. Explain the importance of Garbage collector ?
11. Can garbage collector claim unmanaged objects ?
12. What is the importance of CTS ?
13. Explain CLS ?
14. What are Value types & Reference types?
15. Explain casting, implicit casting and explicit casting ?
16. What can happen during explicit casting ?
17. Differentiate between Array and ArrayList ?
18. Whose performance is better array or arraylist ?
19. What are generic collections ?
20. What are threads (Multithreading)?
21. How are threads different from TPL ?
22. How do we handle exceptions in C#(try/catch)?
23. What is the need of finally?
24. Why do we need the out keyword ?

Questions on OOPs concept

1. Why do we need OOP ?
2. What are the important pillars of OOPs ?
3. What is a class and object ?
4. Abstraction vs Encapsulation?
5. Explain Inheritance ?
6. Explain virtual keyword ?
7. What is overriding ?
8. Explain overloading ?
9. Overloading vs Overriding ?
10. What is polymorphism ?
11. Can polymorphism work with out inheritance ?
12. Explain static vs dynamic polymorphism ?
13. Explain operator overloading ?
14. Why do we need Abstract classes ?
15. Are Abstract methods virtual ?
16. Can we create a instance of Abstract classes ?
17. Is it compulsory to implement Abstract methods ?
18. Why simple base class replace Abstract class ?
19. Explain interfaces and why do we need it ?
20. Can we write logic in interface ?
21. Can we define methods as private in interface ?
22. If i want to change interface what’s the best practice ?
23. Explain Multiple inheritance in Interface ?
24. Explain Interface Segregation principle ?
25. Can we create instance of interface ?
26. Can we do Multiple inheritance with Abstract classes ?
27. Difference between Abstract Class & Interfaces?
28. Why do we need constructors ?
29. In parent child which constructor fires first ?
30. How are initializers executed ?
31. How are static constructors executed in Parent child ?
32. When does static constructor fires ?
33. What is Shadowing?
34. Explain method hiding?
35. Shadowing vs Overriding ?
36. When do we need Shadowing ?
37. Explain Sealed Classes ?
38. Can we create instance of sealed classes ?
39. What are nested classes and when to use them ?
40. Can Nested class access outer class variables ?
41. Can we have public, protected access modifiers in nested class ?
42. Explain Partial classes ?
43. In What scenarios do we use partial classes ?

Questions on Advance C#

1. What are the different types of “USING/HAS A” relationship ?
2. What is a composition relationship ?
3. Explain Aggregation ?
4. Explain Association ?
5. Differentiate between Composition vs Aggregation vs Association ?
6. UML Symbols for Composition, Aggregation and Association
7. Explain stack and Heap ?
8. Where are stack and heap stored ?
9. What goes on stack and what goes on heap ?
10. How is the stack memory address arranged ?
11. How is stack memory deallocated LIFO or FIFO ?
12. How are primitive and objects stored in memory?
13. Can primitive data types be stored in heap ?
14. Explain value types and reference types ?
15. Explain byval and byref ?
16. Differentiate between copy byvalue and copy byref ?
17. What is boxing and unboxing ?
18. What is consequence of boxing and unboxing ?
19. Can we avoid boxing and unboxing ?
20. What effect does boxing and unboxing have on performance ?
21. Are string allocated on stack or heap ?
22. How many stack and heaps are created for an application ?
23. How are stack and heap memory deallocated ?
24. Who clears the heap memory ?
25. Where is structure allocated Stack or Heap ?
26. Are structures copy byval or copy byref ?
27. Can structures get created on Heap ?

Questions on Garbage collectors

1. Explain Garbage collector (GC)?
2. How does Garbage collector know when to clean the objects ?
3. Is there a way we can see this Heap memory ?
4. Does Garbage collector clean primitive types ?
5. Managed vs UnManaged code/objects/resources?
6. Can garbage collector clean unmanaged code ?
7. Explain Generations  ?
8. What is GC0,GC1, and  GC2 ?
9. Why do we need Generations ?
10. Which is the best place to clean unmanaged objects ?
11. How does GC behave when we have a destructor ?
12. What do you think about empty destructor ?
13. Explain the Dispose Pattern?
14. Finalize vs Destructor ?
15. What is the use of using keyword ?
16. Can you force Garbage collector ?
17. Is it a good practice to force GC ?
18. How can we detect a memory issues ?
19. How can we know the exact source of memory issues ?
20. What is a memory leak ?
21. Can .NET Application have memory leak as we have GC?
22. How to detect memory leaks in .NET applications ?
23. Explain weak and strong references ?
24. When will you use weak references ?

Questions on Deletegates and Events

1. What is a delegate and How to create a delegate ?
2. Where have you used delegates ?
3. What is a Multicast delegates ?
4. What is a Event ?
5. How to create a event ?

Questions on Design Principles

1. What is SOLID ?
2. What is the full form of SOLID ?
3. What is the goal of SOLID ?
4. Explain SRP with A example ?
5. What is the benefit of SRP ?
6. Explain OCP with a example ?
7. What is the  benefit of OCP ?
8. Can you explain LISKOV Principle and it’s violation?
9. How can we fix LISKOV Problem ?
10. Explain Interface Segregation Principle ?
11. Is there a connection between LISKOV and ISP ?
12. Define dependency inversion ?
13. What is higher level module and lower level module ?
14. How does dependency inversion benefit, show with an example ?
15. Will only Dependency inversion solve decoupling problem ?
16. Why do developers  move object creation outside high lever module ?
17. Explain IOC ( Inversion of Control) ?
18. Explain Dependency Injection with an example ?
19. Is SOLID, IOC and DI design pattern or Principle?
20. Is only SOLID Enough for good code/ architecture ?

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