#CsharpInterviewQuestions2021

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CoVariance vs. ContraVariance and InVariance vs. Variance in C#:

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Q01. What do you understand by Variance in C#?

Q02. What is InVariance in C#?

Q03. What is CoVariance in C#? Do you know any real covariant examples available in C#?

Q04. What is ContraVariance in C#? Do you know any real contravariant examples available in C#?

Q05. What is the difference between CoVariance and ContraVariance in C#?

Q06. What is Variant Generic Interface?

Q07. What is Variant Generic Delegate?

Q08. What is a CoVariant Array?

Q09. What is the use of IN and OUT Keyword in C#?

Q10. What is Liskov Substitute Principle?

Q11. What do you understand by More Derived vs. Less Derived Type in C#?

Q12. What is the difference between Dynamic Polymorphism, SubTyping Principle, Liskov Substitute Principle, and Variance feature in C#?

https://www.techpointfunda.com/2021/10/covariance-vs-contravariance.html

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IDisposable vs. Destructor in C#:

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Difference Between "==" vs .Equals() Method C# | == vs Equals() | Equali...

Equality Operator (==) vs. .Equals() Method Comparison C#: --------------------------------------------------------------------------------

Q01. What is the difference between Equality Operator (==) and .Equals() method Comparison in C#?

Q02. Can you use the .Equals() method to compare value types in C#?

Q03. Can you use the  Equality Operator (==) to compare structure objects in C#?

Q04. Can you use the  Equality Operator (==) to compare class objects in C#?

Q05. I have two objects of a class, how can you check and confirm that both objects are the same?

Q06. What is the type of string in C#, value type or a reference type?

https://www.youtube.com/watch?v=BG4TQ8AQ300

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Destructor vs. Finalizer in C#:

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Sealed Class and Sealed Methods in C#

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Q001. What are the 4 pillars of OOPS? Q002. What is the difference between Abstraction and Encapsulation? Q003. What is the difference between Class and Structure in C#? Q004. What are the different Access Modifiers in C#? Q005. What is Polymorphism in C#? What are the different types of Polymorphism? Q006. What are the different ways to implement Polymorphism in C#? Q007. What is the difference between Early Binding and Late Binding in C#? or What is the difference between Compile Time Polymorphism and Run-Time Polymorphism in C#? Q008. What is Shadowing in C#? or What is the Method Hiding in C#? How can you achieve that? Q009. What is the abstract method? How an abstract method is different from the virtual method? Q010. What is the difference between Overloading and Overriding in C#?

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Typeof vs Nameof Operator C# | Typeof Operator vs GetType Method C# 

Q01. What is the difference between 'Typeof' and 'Nameof' operators in C#? Q02. What is the difference between Typeof and GetType() method in C#? Q03. What is the difference between TypeOf and 'IS' operators in C#? Q04. What is the main issue of 'TypeOf' operator in C#? Q05. Can you overload the 'TypeOf' operator in C#?   Q06. Which operator would you use to check the type of an object at run-time? Q07. What is the the use of GetType() method in C#? Q08. What is the 'TypeOf' operator in C#? Q09. What is the 'NameOf' operator in C#? Q10. What is the difference between TypeOf and 'AS' operators in C#?

https://youtu.be/oO9tCIZ_CH4

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IS vs AS Operator C# | Casting vs AS Operator | Conversion vs AS Operator

IS vs AS Operator C#: ----------------------------- Q01. What is the difference between 'IS' and 'AS' operators in C#? Q02. What is the difference between Conversion and 'AS' operators in C#? Q03. What is the difference between Casting and 'AS' operators in C#? Q04. What is the main issue of 'IS' operator in C#? Q05. Can you overload the 'IS' and 'AS'operators in C#?   Q06. Which operator would you use to check the type of an object at run-time? Q07. Can you use 'AS' operator for value types? Why? Q08. What is the 'IS' operator in C#? Q09. What is the 'AS' operator in C#? Q10. Why explicit operators when we have already Cast operator, Convert and Parse Methods in .Net?

https://www.youtube.com/watch?v=OE0nxcUzxGo

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Boxing vs UnBoxing | Conversion vs Boxing | Casting vs UnBoxing | Stacki...

Boxing vs UnBoxing and Conversion vs Boxing and Casting vs UnBoxing: -------------------------------------------------------------------------------------------------- Q01. What is the difference between Boxing and UnBoxing in C#? Q02. What is the difference between Conversion and Boxing in C#? Q03. What is the difference between Casting and UnBoxing in C#? Q04. What is the difference between Value Type and Reference Type in C#?   Q05. Can you give me some real examples of boxing and unboxing in C#? Q06. What are Boxing and Unboxing in  C#? Q07. Why generic collections are preferred over non-generic collections? Q08. What is System.Object in the .Net Framework? Q09. Where do the value types stored in the memory? Q10. What is the difference between Stack and Heap? Q11. How do Boxing and Unboxing affect the performance of the application? Q12. Is storing enum value to object type an example of Boxing? Q13. Does Boxing happen for the reference data types in C#? Q14. Does the conversion of a string to object type an example of Boxing? Q15. If Boxing-Unboxing causes overhead, then why Boxing and Unboxing are there in the .Net? or What is the real need for Boxing and Unboxing in .Net? Q16. If you change the value of the boxed object, does it also affect the original value type value and vice-versa? Q17. A string is a reference type or value type in C#?

https://youtu.be/lruQ-1X4JWk

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Conversion vs Casting vs Parsing in C# | Convert vs Parse vs TryParse in...

Conversion vs Casting vs Parsing in C#: ----------------------------------------------------- Q01. What is the difference between Conversion, Casting, and Parsing in C#? Q02. What is the difference between Narrowing Conversion and Widening Conversion in C#? Q03. What is the difference between Upcasting and Downcasting in C#? Q04. What is the difference between Type Conversion and Type Casting in C#? Q05. What is the difference between Implicit Conversion and Explicit Conversion? Q06. Does the Implicit Conversion possible for the reference data types like class and interface in C#? Q07. What is the difference between Implicit Casting and Explicit Casting? Q08. Type Casting is the compile-time process or a run-time process? Q09. Does Casting involve any conversion? Q10. Does the internal data structure changes in the typecasting process? Q11. What is the difference between the Type Conversion and available Convert functions in the .Net framework? Q12. Does Conversion or Casting possible between different data types (heterogeneous types)?

https://youtu.be/XjvWRR3NRHU

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Constructor Execution Sequence in C# | Instance vs Static Constructor Ex...

Constructors Execution Sequence Order: -------------------------------------------------------- Q01. What is the Constructor Execution Sequence Order in C#? Q02. What is the Class Constructor Execution Sequence Order in C#? Q03. What is the Structure Constructor Execution Sequence Order in C#? Q04. What is the Static Constructor Execution Sequence Order in C#? Q05. What is the Structure Static Constructor Execution Sequence Order in C#? Q06. What is the Constructor Execution Sequence Order in the parent-child class hierarchy? Q07. What is the Static Constructor Execution Sequence Order in the parent-child class hierarchy? Q08. If the parent class constructor is called first, then what is the order of the class member variables initialization?

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Sealed Method Interview Questions and Answers: