16 C# Interview Questions to Practice
Whether you’re drawn to C# for its versatility, usability, or the ease with which you can transition to it from C++, C# is a powerful, effective programming language. Many types of programmers, especially Game Developers, commonly use it because of the speed and consistency it gives your coding.
Plus, not only is C# a fun and convenient language, but it can also net you a pretty impressive salary. C# Developers earn an average of $112,952 a year.
To land a six-figure C# job, you’ll have to perform well during the interview. Below, you’ll find some C# interview questions to practice, as well as their answers, so you can walk into your next interview with confidence.
1. What is C#?
C# is a programming language that’s object-oriented and type-safe. This means that the program will catch errors as you make them, preventing you from wasting time fixing minor problems later on.
It’s compiled with the .Net framework to generate Microsoft Intermediate Language (MSIL), which is a set of instructions that can run on multiple environments.
2. Can you execute more than one catch block?
No, you cannot execute multiple types of catch blocks. Once you’ve executed the proper catch code, the control gets transferred over to a final block. The code after that final block is what gets executed.
3. What are jagged arrays?
Jagged arrays have elements of tape arrays, and these can include different sizes and dimensions. They’re also referred to as arrays of arrays.
4. What’s the difference between void, public, and static?
If you have a public declared variable or method, it’ll be accessible anywhere inside the application. On the other hand, you can access static declared variables or methods without having to create an instance of a class. Void is different in that it’s a type modifier that says the variable or method doesn’t return a value.
5. What differentiates a constant from a read-only?
Constant variables get initialized and declared when it’s time to compile the code. After that, you can’t alter their values. Read-only refers to when you assign a value at run-time.
6. What’s an object?
An object refers to a class instance that allows you to access the methods pertaining to that class. If a class creates an object in memory, it’ll contain all of the information about the class’s variables, methods, and behavior.
7. What is a “using” statement in C#?
A “using” block is used to get a resource and process it but then dispose of it automatically after completing the block.
8. What do sealed classes refer to in C#?
Sealed classes are created when you want to restrict which class is going to get inherited. You’d use sealed modifiers to prevent deviation from a class. If you chose a sealed class to be a base class, you’d get a compile-time error.
9. What’s the difference between “out” and “ref” parameters?
An argument that’s passed as ref has to be initialized before it’s passed to the method. On the other hand, out parameters don’t have to be initialized before getting passed to a method.
10. What’s meant by method overloading?
Overloading refers to creating multiple methods that have the same name and unique signatures within the same class. During compilation, the compiler can use overload resolution to determine which method you need to invoke.
11. Describe the difference between array and arraylist
Items within an array have the same type. The size of an array is fixed. An arraylist is similar, except it doesn’t have a fixed size.
12. Are you able to use a “this” command within the context of a static method?
No, you cannot use a “this” command in a static method because you can only use static methods and variables in a static method.
13. What’s the accessibility modifier “protected internal”?
You can access protected internal methods and variables from within the same assembly. Also, you can access them from classes that have been derived from the parent class.
14. What’s meant by “serialization”?
Serialization refers to the process you use when you want to move an object through your network and have to convert it into a stream of bytes.
For an object to be eligible for serialization, it has to implement the ISerialize Interface. When you do the opposite operation — start with a stream of bytes and use it to create an object — you call the process de-serialization.
15. What’s the difference between System.Text.StringBuilder and System.String classes?
System.String isn’t mutable. As an immutable class, you can’t change its value without allocating new memory to the new value and releasing the previous allocation.
System.StringBuilder has a mutable string. This makes it possible to perform a variety of operations without having to allocate a separate memory location for the string you modified.
16. What’s the difference between System.Array.Clone() and System.Array.CopyTo()?
If you use Clone(), you create a fresh array object that has all the elements of the original array. When you use the CopyTo() technique, the elements of an existing array get copied into another existing array. With both methods, a shallow copy gets performed.
How to go beyond C# interview questions
Take your time and practice answering these questions to get ready to nail your next interview. If you still need a little help understanding the ins and outs of C#, check out our Learn C# course.
Depending on what role you’re applying for, your interview process may also include technical interviews, in which you’ll showcase your programming skills by completing coding challenges. Need help preparing for technical interviews? Check out our Career Center.