Top C# Interview Questions for Experienced Professionals

Prepare the most anticipated C# interview questions and answers for experienced professionals to increase your chances of landing a job at the top companies that use C# in their tech stacks, such as Accenture, Google, Delivery Hero, Wipro, Infosys, HCL, TCs, Microsoft, Stack Overflow, Intuit, and Trustpilot.

C# is a programming language ideal for general purposes as it encompasses several disciplines such as object-oriented programming, component-oriented programming, static and strong typing. C# is popularly used in the ASP.NET framework as it is ideal for creating web applications, websites, and games. Continue reading to discover the most frequently asked C# interview questions and answers for experienced professionals.  

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Here's what we'll cover:

• C# Interview Questions and Answers for Experienced Professionals
• Sample C# Interview Questions for Experienced Professionals
• C# Interview Questions for Professionals with 10 Years Experience
• FAQs on C# Interview Questions and Answers for Experienced Professionals

C# Interview Questions and Answers for Experienced Professionals

The key concepts in the following list of C# interview questions and answers for experienced professionals are explained simply and easily to help you ace your next job interview.

Q1. How is Exception Handling implemented in C#?

You can carry out exception handling using the following four keywords in C#:

• try: It has a code block for which an exception is checked.
• catch: This program catches an exception with the assistance of an exception handler.
• finally: It is a code block written to execute irrespective of the exception being caught or not.
• throw: It throws an exception whenever a problem takes place.

Q2. How is encapsulation implemented in C#?

You can implement encapsulation by using access specifiers that define the scope and visibility of a class member. Some access specifiers are as follows:

• Public access specifier: It allows a class to expose its member functions and variables to other objects and functions. It allows access to any public member from outside the class.
• Private access specifier: It allows a class to hide its member functions and variables from other objects and functions. It allows only functions of the same class to access its private members.
• Protected access specifier: It allows a child class to access its base class's member function and variables, thus helping in inheritance implementation.

Q3. How is overloading different from overriding?

The following table enumerates the key differences between overloading and overriding.

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Q4. What do you understand about method shadowing or method hiding in C#?

Shadowing or method hiding in C# is a VB.Net concept hiding the implementation of the base class method. You can achieve method shadowing using the 'new' keyword. If a method does not override the derived method, it hides it.

Q5. What are generics in C#.NET?

Generics are classes that allow you to define classes and methods with a placeholder. The purpose of generics is to make reusable code classes. These classes decrease code redundancy and increase performance and type safety.

Generics promotes the usage of parameterized types. You can also create collection classes using generic. System.Collections.The generic namespace is used instead of classes to create a generic collection.

Take a look at the top .NET Interview Questions and Answers that you need to prepare.

Q6. What do you understand about dependency injection?

You can de-couple tightly linked classes using the dependency injection. Thus, it reduces the direct dependency of classes upon each other. You can achieve dependency injection via the following:

• Constructor dependency
• Property dependency
• Method dependency

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Q7. What do you understand about Polymorphism in C#?

This is one of the most commonly asked C# interview questions and answers for experienced professionals. Polymorphism is one of the three main pillars of object-oriented programming after encapsulation and inheritance.

The term polymorphism means "many shapes." It occurs when there are many classes related to each other by inheritance.

For instance, at runtime, derived class objects may be treated as base class objects in places like collections/ method parameters/ arrays. In such polymorphism, declared and runtime types of objects are different. Thus, polymorphism allows a class to have multiple implementations with the same name.

Q8. Is it possible to serialize hashtables?

No, you cannot serialize a hashtable because the .NET Framework doesn't allow the serialization of an object that implements the IDictionary interface.

Q9. What is Satellite Assembly?

A compiled library (DLL) containing localizable resources specific to a given culture like strings and bitmaps is referred to as a Satellite Assembly. You can use satellite assemblies while creating a multilingual UI application.

Q10. What is interface inheritance?

Interface inheritance is when a class inherits only the signatures of the functions from another class. It is also called type inheritance/ subtyping. It allows code reuse and polymorphism. The main advantage of interface inheritance is that it reduces coupling and implementation dependencies.

Q11. What are the advantages of using partial classes?

The major advantages of using partial classes are as follows:

• They allow multiple developers to work on the same class easily.
• The code generators mainly use them to keep different concerns separate.
• It allows one developer to define the method while the other developer can implement it.

Q12.  What is string interpolation in C#?

String Interpolation in C# allows to create formatted strings with readable and convenient syntax. You can create an interpolation string containing interpolation expressions using the $ special character. On resolving, the interpolation string replaces the interpolation expression with the string representation of the interpolation item.

Q13. What are Covariance and Contravariance in C#?

While covariance allows a method to have a return type, a subtype of the one defined in the delegate, contravariance allows a method to have a parameter type, i.e., a base type of the one defined in the delegate type.

Q14. What do structs and classes have in common, and how do they differ?

Classes and Structs have the following in common:

• They are compound data types.
• They can contain events and methods.
• They support interfaces

The key differences between structs and classes are as follows:

Sample C# Interview Questions for Experienced Professionals

Practice the following C# interview questions for experienced professionals.

1. What do you understand about boxing and unboxing?
2. Is it possible to store mixed data types such as string, int, float, and char in one array?
3. What is a race condition in C#?
4. How would you force Garbage Collection?
5. How is Lock different from Monitor in C#?
6. How is Var different from Dynamics in C#?
7. When would you use Tuples in C#?
8. How would you create a responsive UI without impacting users?
9. Why is the singleton pattern referred to as an anti-pattern?
10. How would you use Nullable Types in .NET?
11. How would you implement a singleton design pattern in C#?
12. What are the key differences between the "throw" and "throw ex" in .NET?

C# Coding Interview Question for Practice

You should be well-versed in data structures and algorithms to ace the C# coding problems in technical interview rounds.  

1. Write a program to reverse a string in C#.
2. How would you reverse the order of the given words in a string?
3. Write a program to find if the given string is palindrome or not?
4. Write a C# program to find if the given number is prime or not.
5. How would you count the occurrence of each character in a string?
6. Write a program to remove duplicate characters.
7. How would you perform the left circular rotation of a given array?

C# Interview Questions for Professionals with 10 years Experience

If you are applying for senior C# developer roles, you should practice the following advanced C# interview questions to outperform the competition.

1. What do you understand about Reflection in C#? What are the common uses of Reflection?
2. What is an Assembly Manifest?
3. How would you generate a random number in C#?
4. How would you split a string using Regex in C#?
5. What is the use of app.config or web.config in C#?
6. What files get generated in Debug folder when you create and compile an application in C#?
7. Is it possible to add extension methods to an existing static class?
8. What are the major differences between Object pooling and Connection pooling in C#?
9. What is the use of volatile keywords?
10. What is the role of the async method in C#?
11. How would you cancel an Async operation in C#?
12. State all the differences between Rectangular and Jagged Array in C#.

This completes our list of the most anticipated C# interview questions and answers for experienced professionals. In addition to these questions, you must practice mock interviews to nail the most challenging technical interviews.

FAQs on C# Interview Questions and Answers for Experienced Professionals

Q1. What topics should I prepare for C# interview questions and answers for experienced professionals?

You should thoroughly practice control statements, arrays, functions, object classes, properties, inheritance, abstraction, polymorphism, CLR, CLS, CTS, and strings exception handling to ace C# interview questions and answers for experienced professionals.

Q2. How should I prepare for C# interview questions and answers for experienced professionals?

You must get well-versed in basic and advanced concepts of C#. Practice the most anticipated interview questions, and practice mock interviews. You must practice multiple coding problems to improve your speed and accuracy.

Q3. What are the main differences between C and C#?

The key difference between C and C# is that the C language can be executed cross-platform, whereas the .NET framework is required to execute the C# language. In the C language, garbage collection is not available, but C# features garbage collection managed by Common Language Runtime (CLR).

Q4. Which companies use C# interview questions and answers for experienced professionals?

Several top companies use C# interview questions and answers for experienced professionals, including Google, Wipro, Infosys, Accenture, JP Morgan, HCL, TCS, and Google.

Q5. What is the average salary of a C# developer in the US?

The salaries of C# developers range from $60,000 to $160,000 in the United States, and the average salary is $80,000 (Source: comparably.com).

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