.NET (DOTNET) Interview

OOPS & C# - Basics

  • Q1. What is C#? What is the difference between C# and .NET?
  • Q2. What is OOPS?What are the main concepts of OOPS?
  • Q3. What are the advantages of OOPS?
  • Q4. What are the limitations of OOPS?
  • Q5. What are Classes and Objects?
  • Q6. What are the types of classes in C#?
  • Q7. Is it possible to prevent object creation of a class in C#?
  • Q8. What is Property?
  • Q9. What is the difference between Property and Function?
  • Q10. What are Namespaces?

OOPS & C# - Inheritance, Abstraction, Encapsulation & Polymorphism

  • Q11. What is Inheritance? When to use Inheritance?
  • Q12. What are the different types of Inheritance?
  • Q13. Does C# support Multiple Inheritance? How to you implement
  • Q14. How to prevent a class from being Inherited?
  • Q15. Are private class members inherited to the derived class?
  • Q16. What is Abstraction? How to implement abstraction in real applications?
  • Q17. What is Encapsulation? How to implement encapsulation in real applications?
  • Q18. What is the difference between Abstraction and Encapsulation?
  • Q19. What is Polymorphism and what are its types? When to use polymorphism?
  • Q20. What is Method Overloading? In how many ways a method can be overloaded?
  • Q21. When should you use method overloading in real applications?
  • Q22. If two methods have same except return type, then methods are overloaded?
  • Q23. What is the difference between Overloading and Overriding?
  • Q24.Use of Overriding? When should I override the method in real applications ?
  • Q25. Method is marked as virtual, do we have to "override" it from the child base
  • Q26. What is the difference between Method Overriding and Method Hiding?

OOPS & C# - Abstract Class & Interface

  • Q27. What is the difference between an Abstract class and an Interface?
    • V.IMP.
  • Q28. When to use Interface and when Abstract class in real applications?
  • Q29. Why to create Interfaces in real applications?
  • Q30.Can we define body of Interfaces methods ?
  • Q31. Can you create an instance of an Abstract class or an Interface?
  • Q32. Do Interface can have a Constructor?
  • Q33. Do abstract class have Constructors in C#?
  • Q34. What is the difference between abstraction and abstract class?
  • Q35. Can Abstract class be Sealed or Static in C#?
  • Q36. Can you declare abstract methods as private in C#?
  • Q37. Does Abstract class support multiple Inheritance?

OOPS & C# - Access Specifiers, Boxing, Unboxing, String & StringBuilder

  • Q38. What are Access Specifiers?
  • Q39. What is internal access modifier?
    • Show example.
  • Q40. What is the default access modifier in a class?
  • Q41. What is Boxing and Unboxing? Where to use them in real applications?
  • Q42. Which one is explicit Boxing or Unboxing?
  • Q43. Is Boxing and Unboxing good for performance?
  • Q44. What are the basic string operations in C#?
  • Q45. What is the difference between “String” and “StringBuilder”?
  • Q46. When to use String and when StringBuilder in real applications?
  • Q47. What is String Interpolation in C#?

OOPS & C# - LOOPS , Conditions, Exception Handling

  • Q48. What are the Loop types in C#? When to use what in real applications?
  • Q49. What is the difference between “continue” and “break” statement?
  • Q50. What are the alternative ways of if-else conditions? When to use what?
  • Q51. How to implement Exception Handling in C#?
  • Q52. Can we execute multiple Catch blocks?
  • Q53. When to use Finally in real applications?
  • Q54. Can we have only “Try” block without “Catch” block?
  • Q55. What is the difference between Finally and Finalize?
  • Q56. What is the difference between “throw ex” and “throw”?

OOPS & C# - Generics & Collections

  • Q57. Explain Generics in C#? When and why to use them?
  • Q58. What are Collections in C# and what are their types?
  • Q59. What is the difference between Array and ArrayList?
  • Q60. What is the difference between ArrayList and Hashtable?
  • Q61. What is the difference between List and Dictionary Collections?
  • Q62. What is IEnumerable in C#?
  • Q63. What is the difference between IEnumerable and IEnumerator in C#?
  • Q64. What is the difference between IEnumerable & IQueryable?

OOPS & C# - Constructors

  • Q65. What is a Constructor? When to use constructor in real applications?
  • Q66. What are the types of constructor?
  • Q67. What is Default constructor?
  • Q68. What is Parameterized constructor?
  • Q69. What is Static constructor? What is the use in real applications?
  • Q70. Can we have parameters or access modifier in static constructor?
  • Q71. What is Copy constructor?
  • Q72. What is Private constructor? What is the use?
  • Q73. What is Constructor overloading?
  • Q74. What is Destructor?
  • Q75. Can you create object of class with private constructor in C#?
  • Q76. If base & child both class have constructors, which will be called first?

OOPS & C# - Method Parameters, Delegates & Events

  • Q77. What is a Method in C#?
  • Q78. Difference between Pass by Value and Pass by Reference Parameters?
  • Q79. How to return more than one value from a method in C#?
  • Q80. What is the difference between “out” and “ref” parameters?
  • Q81. What is “params” keyword? When to use params keyword in real applications?
  • Q82. What are optional parameters in a method?
  • Q83. What are named parameters in a method?
  • Q84. What are extension Methods? When to use them? V Imp
  • Q85. What are Delegates in C#? When to use delegates in real applications?
  • Q86. What are Multicast Delegates?
  • Q87. What are Anonymous Delegates in C#?
  • Q88. What are the differences between Events and Delegates?

OOPS & C# - Important Keywords

  • Q89. What is “this” keyword in C#? When to use it in real application?
  • Q90. What is the purpose of “using” keyword in C#?
  • Q91. Can we use Using keyword with other classes apart from DB Connection?
  • Q92. What is the difference between “is” and “as” operators?
  • Q93. What is the difference between “Readonly” and “Constant” variables?
  • Q94. What is “Static” class? When to use it?
  • Q95. What is the difference between “var” and “dynamic” in C#?
  • Q96. What is Enum keyword used for?
  • Q97. Is it possible to inherit Enum in C#?
  • Q98. What is the use of Yield keyword in C#?

OOPS & C# - LINQ

  • Q99. What is LINQ? When to use LINQ in real applications?
  • Q100. What are the advantages & disadvantages of LINQ?
  • Q101. What is Lambda Expressions? What is the use in real applications?
  • Q102. What is the difference between First and FirstOrDefault methods in LINQ?

.NET Framework - Basics

  • Q103. What are the important components of .NET framework?
  • Q104. What is an Assembly? What are the different types of assembly in .NET?
  • Q105. What is GAC?
  • Q106. What is Reflection?
  • Q107. Serialization and Deserialization? What are the types of serialization?
  • Q108. What is meant by Globalization and Localization?
  • Q109. What are Window Services?

.NET Framework - Garbage Collection

  • Q110. What is Garbage Collection(GC)?
  • Q111. What are Generations in garbage collection?
  • Q112. What is the difference between “Dispose” and “Finalize”?
  • Q113. What is the difference between “Finalize” and “Finally” methods?
  • Q114. Can we force Garbage Collector to run?

.NET Framework - Threading

  • Q115. What is the difference between Process and Thread?
  • Q116. Explain Multithreading?
  • Q117. What is the difference between synchronous and asynchronous programming?
  • Q118. Difference between Threads & Tasks? Advantages of Tasks over threads ?
  • Q119. What is the role of Async and Await ?

SQL - Basics

  • Q120. What is the difference between DBMS and RDBMS?
  • Q121. What is a Constraint is SQL? What are its types.
  • Q122. What is the difference between Primary key and UniQue key?
  • Q123. What are Triggers and types of triggers?
  • Q124. What is a View?
  • Q125. What is the difference between Having clause and Where clause?
  • Q126. What is Sub Query or Nested Query or Inner Query in SQL?
  • Q127. What is Auto Increment/ Identity column in SQL Server?

SQL - Joins & Indexes

  • Q128. What are Joins in SQL?
  • Q129. What are the types of Joins in SQL Server?
  • Q130. What is Self-Join?
  • Q131. What are Indexes in SQL Server?
  • Q132. What is Clustered index?
  • Q133. What is Non-Clustered index?
  • Q134. What is the difference between Clustered and Non-Clustered index?
  • Q135. How to create Clustered and Non-Clustered index in a table?
  • Q136. In which column you will apply the indexing to optimize this Query?

SQL - Stored Procedure, Functions & Others

  • Q137. What is the difference between Stored Procedure and Functions?
  • Q138. How to optimize a Stored Procedure or SQL Query?
  • Q139. What is a Cursor? Why to avoid them?
  • Q140. What is the difference between scope identity and @@identity?
  • Q141. What is CTE in SQL Server?
  • Q142. What is the difference between Delete, Truncate and Drop commands?
  • Q143. How to get the Nth highest salary of an employee?
  • Q144. What are ACID properties?
  • Q145. What are Magic Tables in SQL Server?

ASP.NET – MVC

  • Q146. What is MVC (Model View Controller)?
    • Explain MVC Life cycle.
  • Q147. What are the advantages of MVC over Web Forms (at least 3)?
  • Q148. What are the different return types of a controller Action method?
  • Q149. What are Filters and their types in MVC?
  • Q150. What is Authentication and Authorization in ASP.NET MVC?
  • Q151. What are the types of Authentication in ASP.NET MVC?
  • Q152. What is Output Caching in MVC? How to implement it?
  • Q153. What is Routing in MVC?
  • Q154. Explain Attribute Based Routing in MVC?
  • Q155. What is the difference between ViewData, ViewBag & TempData?
  • Q156. How can we pass the data from controller to view in MVC?
  • Q157. What is Partial View?
  • Q158. What are Areas in MVC?
  • Q159. How Validation works in MVC? What is Data Annotation?
  • Q160. Explain the concept of MVC Scaffolding?
  • Q161. What is Bundling and Minification in MVC?
  • Q162. How to implement Security in web applications in MVC?

ASP.NET Webforms

  • Q163. What are the events in Page Life Cycle? In which event the controls loaded
  • Q164. What is the difference between Server.Transfer() and Response.Redirect()?
  • Q165. What are the different types of Caching?
  • Q166. What are the types of state management?
  • Q167. Where the ViewState is stored after the page postback?
  • Q168. What are the different ways to store session state in asp.net?
  • Q169. What is cookie less session?
  • Q170. How to force all the validation controls to run in a page in web forms?

ADO.NET and Entity Framework

  • Q171. What are the main components of ADO.NET?
  • Q172. What is Connected architecture and Disconnected architecture?
  • Q173. What are the different Execute Methods of ADO.NET?
  • Q174. What are the Authentication techniQues used to connect to SQL Server?
  • Q175. What is ORM? What are the different types of ORM?
  • Q176. What is Entity Framework?
  • Q177. How will you differentiate ADO.NET from Entity Framework?
  • Q178. How Entity Framework works? OR How to setup EF?
  • Q179. What is meant by DBContext and DBSet?
  • Q180. What are the different types of development approaches used with EF?
  • Q181. What is the difference between LINQ to SQL and Entity Framework?

Web API - Basics

  • Q182. What is Web API? What is the purpose of Web API?
  • Q183. What are Web API advantages over WCF and web serivces?
  • Q184. What are HTTP verbs or HTTP methods?
  • Q185. What is the difference Rest API and Web API?
  • Q186. What are REST guidelines? What is the difference between Rest and Restful?
  • Q187. Is it possible to use WCF as Restful services?
  • Q188. How to consume Web API from a .NET MVC application?
  • Q189. What is the difference between Web API and MVC Controller?

Web API - Authentication & JWT

  • Q190. What are the types of authentication techniQues in web API?
  • Q192. What is API Key Authentication in Web API?
  • Q193. What is Token based authentication?
  • Q194. What is JWT Authentication?
  • Q195. What are the parts of JWT token?
  • Q196. Where JWT token reside in the re
  • Quest?

Web API - More

  • Q197. How to test Web API? What are the tools?
  • Q198. What are main Return Types supported in Web API?
  • Q199. What is the difference between HTTPResponseMessage and IHttpActionResult?
  • Q200. What is the difference between IActionResult and IHttpActionResult?
  • Q201. What is Content Negotiation in Web API?
  • Q202. What is MediaTypeFormatter class in Web API?
  • Q203. What are Response Codes in Web API?

.NET Core - Basics

  • Q204. What is .NET Core?
  • Q205. What is .NET Standard?
  • Q206. What are the advantages of .NET Core over .NET framework?
  • Q207. What is the role of Program.cs file in ASP.NET Core?
  • Q208. What is the role of ConfigureServices method?
  • Q209. What is the role of Configure method?
  • Q210. Describe the complete Re
  • Quest Processing Pipeline for ASP.NET Core MVC?
  • Q211. What is the difference between .NET Core and .NET 5?
  • Q212. What is Metapackage? What is the name of Metapackage in ASP.NET Core?

.NET Core - Dependency Injection

  • Q213. What is Dependency Injection?
  • Q214. How to implement Dependency injection in .NET Core?
  • Q215. What are the advantages of Dependency Injection in .NET Core?
  • Q216. How to use Dependency Injection in Views in ASP.NET Core?

.NET Core - Service Lifetimes, Middleware & Hosting

  • Q217. What are the types of Service Lifetimes of an object/ instance in ASP.NET
  • Q218. What is AddSingleton, AddSoped and AddTransient method?
  • Q219. What is Middleware in ASP.NET Core? What is custom middleware?
  • Q220. How ASP.NET Core Middleware is different from HttpModule?
  • Q221. What is Re
  • Quest Delegate?
  • Q222. What is Run(), Use() and Map() method?
  • Q223. What are the types of Hosting in ASP.NET Core?
    • What is In process and Out
  • Q224. What is Kestrel? What is the difference between Kestrel and IIS?

.NET Core - Routing, Files, CORS & More

  • Q225. What is Routing? Explain attribute routing in ASP.NET Core?
  • Q226. Explain default project structure in ASP.NET Core application?
  • Q227. How ASP.NET Core serve static files?
  • Q228. What are the roles of Appsettings.Json and Launchsetting.Json file?
  • Q229. What are the techni
  • Ques to save configuration settings in .NET Core
  • Q230. What is CORS? Why CORS restriction is reQuired? Hot to fix CORS error?
  • Q231. What is In-Memory caching & Distributed Caching? When to use what?
  • Q232. How to handle errors in ASP.NET Core?
  • Q233. What are Razor pages in .NET Core?

SOLID Principles

  • Q234. What are SOLID Principles? How they different from Design Patterns?
  • Q235. What is Single Responsibility Principle?
  • Q236. What is Open-closed Principle?
  • Q237. What is Liskov Substitution Principle?
  • Q238. What is Interface Segregation Principle?
  • Q239. What is Dependency Inversion Principle?
  • Q240. What is DRY principle?

Design Patterns

  • Q241. What are Design Patterns and what problem they solve?
  • Q242. What are the types of Design Patterns?
  • Q243. What are Creational Design Patterns?
  • Q244. What are Structural Design Patterns?
  • Q245. What are Behavioral Design Patterns?
  • Q246. What is Singleton Design Pattern?
  • Q247. How to make singleton pattern thread safe?
  • Q248. What is Factory pattern? Why to use factory pattern?
  • Q249. How to implement Factory method pattern?
  • Q250. What is Abstract Factory pattern?
© Copyrite MieWork. All Rights Reserved Developed By Mi eWork