46 C# data structure interview questions 

If you’re hiring a C# developer for your team, one question may be at the forefront of your mind: Does the potential next new hire have the right C# data structure skills to excel in this developer role?

To find out, you will need an in-depth assessment process to evaluate their abilities. How should you do that, though? The answer you need is in this article.

In this article, you’ll find a comprehensive list of 46 C# data structure interview questions that you can ask candidates during interviews. It also covers the basics of using skills testing alongside interviews.

Read until the end to get all the information you need.

9 general C# data structure interview questions

Ask candidates these general interview questions about data structures in C#  to learn about their overall understanding and experience.

1. Explain what data structure means.

2. Which skills and knowledge do you need to understand C# data structures?

3. Describe your experience with C# data structures.

4. How is data structure implementation done in C#?

5. Why have you chosen a career in programming?

6. How do you stay up to date on C# data structure concepts?

7. Why are data structures important?

8. What is a non-linear data structure?

9. What is a linear data structure?

5 general C# data structure interview questions and answers

Here’s a selection of five of the  general C# data structure interview questions above, along with sample answers to help you assess applicants’ knowledge.

1. Which skills and knowledge do you need to understand C# data structures? 

Candidates should know that skills in object-oriented programming are critical for understanding C# data structures. They should also know how to program in C#.

2. Why are data structures important?

There are three reasons why data structures are important. Candidates should know that data structures enhance the efficiency of coding programs. 

Can your applicants also explain that data structures are also the best way to organize information and that they let the program retrieve data quickly?

3. What is a linear data structure?

A linear data structure is a data type made of elements that form a linear list. Applicants should know some examples of non-linear data structures, such as arrays, linked lists, stacks, and queues.

4. What is a non-linear data structure?

A non-linear data structure is a data structure where elements are arranged non-linearly. A couple of examples of non-linear data structures that candidates may mention include trees and graphs.

5. Explain what data structure means.

Data structure refers to arranging data strategically in such a way that developers can use it efficiently. There are different types of data structures, such as B-trees or hash tables.

28 C# data structure interview questions about terms and definitions

A thorough understanding of key data structure terms and definitions is critical for C# developers.

To assess candidates’ knowledge in this area, ask them some of the 28 C# data structure interview questions below.

1. Can you explain what LIFO means?

2. Can you explain what binary trees are?

3. Can you explain what complete binary trees are?

4. What is a full binary tree?

5. Explain what a stack is.

6. Explain what a binary search tree is.

7. Can you explain what a multidimensional array is?

8. What are C# arrays?

9. What are some of the characteristics of C# arrays?

10. How is a file structure different from a storage structure?

11. Is a stack a recursive data structure?

12. Explain what a Heap is.

13. Explain a situation when a linked list is handy.

14. Explain how Heaps are different to arrays when implementing priority queues.

15. Explain what a balanced tree is.

16. Explain what a max-heap is.

17. What is a queue?

18. Explain what a graph is.

19. Explain what a bipartite graph is.

20. What is a BFS graph?

21. What is a DFS graph?

22. What is a singly linked list?

23. What is a doubly linked list?

24. What is a circular linked list?

25. What does the insertion operation do to C# data structures?

26. What does the deletion operation do to C# data structures?

27. What does the searching operation do to C# data structures?

28. What does the sorting operation do to C# data structures?

5 C# data structure interview questions and answers about terms and definitions

Here are five critical C# data structure interview questions about terms and definitions from the list above, along with answers you should look for during the interview.

1. What are C# arrays?

Arrays in C# are structures that represent and store a fixed number of elements (or literal values) that are the same type of data. There are a few different types of arrays in C#. Candidates may mention three different examples: jagged, single, and multidimensional arrays.

2. What are some of the characteristics of C# arrays?

Some of the main characteristics of C# arrays that candidates may describe include:

• Fixed size: C# arrays have a limited number of literal values

• Order or storage: C# arrays are stored in a linear order

• Homogeneous characteristics: C# arrays are all the same type of data

3. What does the insertion operation do to C# data structures?

Your candidates should be able to explain that the insertion operation adds a new item of data to the collection of data items in C# data structures.

4. What does the deletion operation do to C# data structures?

Applicants should know that the deletion operation deletes a data item from the collection of data items in C# data structures.

5. What does the searching operation do to C# data structures?

Your applicants should be able to explain that the searching operation helps developers locate a data item in the data items collection (if it exists).

9 C# data structure interview questions about processes

Ask your candidates some of these nine C# data structure interview questions about processes to learn more about how they approach challenges with C#.

1. How would you join one linked list to another?

2. How would you remove a duplicate from a linked list?

3. Which method would you use to implement a queue with stacks?

4. Which method would you use to implement a stack using queues?

5. Which method would you use to find a stack’s lowest value?

6. In which situation would you use queue data structures and not arrays?

7. How would you reverse a linked list?

8. Which data structure would you use for a graph’s Breadth-First Search (BFS)?

9. Which data structure would you use for a Depth-First Search (DFS) algorithm?

5 C# data structure interview questions and answers about processes

Here are five key C# data structures interview questions about processes from the list above, along with the answers you should listen for during the interview.

1. Which data structure would you use for a graph’s Breadth-First Search (BFS)?

Your candidates should know that queue data structures are the best option for storing nodes in the breadth-first search of a graph.

2. Which data structure would you use for a graph’s Depth-First Search (DFS)?

Applicants should be able to explain that stack data structures are the ideal option for DFS of a graph, but that developers can also use recursion to implement DFS.

3. How would you remove a duplicate from a linked list?

Can your applicants explain that they should use the removeDuplicates() function to remove duplicates from a linked list? They may also mention that the function returns a linked list without duplicate nodes.

4. Which method would you use to implement a queue with stacks?

Applicants should be able to explain that using the myStack class is the first step to implementing a queue with stacks. They should then explain that they would implement the enqueue() function, which returns true from an integer after it inserts a value into the queue.

5. Which method would you use to implement a stack using queues?

Candidates should know that it’s possible to use two queues to implement a stack. They may explain that developers can either make a push operation (inserting an element in the stack) or a pop operation (removing an element from the stack) to implement stacks. 

Which skills are crucial when hiring a C# developer?

When hiring a C# developer, you should look for four critical skills: 

• C# language programming skills

• Problem solving

• Code quality evaluation

• Critical-thinking skills

1. C# language programming skills

Can your applicants prove they have the C# language programming skills your organization requires, including C# data structure knowledge? Can they demonstrate that they understand object-oriented programming and have the right experience in this area?

2. Problem-solving skills

Do your applicants have the right problem-solving aptitudes to efficiently build mobile, game, or enterprise applications and software in C#? Can they solve problems related to data structures and show that they can take complex issues and break them down to solve them efficiently when programming apps?

3. Code quality evaluation

How advanced are your candidates’ code quality evaluation skills? Can they deduce where bugs may be located and debug code successfully? Can they confidently assess other developers’ code to evaluate the quality?

4. Critical-thinking skills

Are your applicants able to find innovative solutions to complex coding problems using critical-thinking skills? Can they implement successful workarounds to develop apps successfully in C#?

5 tips for using C# data structure interview questions

Use these five tips below to simplify the hiring process and hire the right candidate.

1. Administer skills assessments before the interview

Don’t begin your recruitment process with interviews – start with skills assessments instead. They can help you better understand your applicants’ technical skills and identify the most promising applicants to invite to an interview.

This way, you’re only spending time interviewing candidates who already have the right knowledge.

2. Start interviews with general C# interview questions

Ask applicants general interview questions at the start of the interview to gauge their experience level with C#.

Recommended reading: 50 C# interview questions to find the best developer

3. Take notes on applicants’ responses

If you decide to take notes during the interview, tell candidates you will be doing so – especially if you are conducting virtual or video interviews.

4. Complete a reference check after you have found a promising candidate

Reach out to previous employers of your top candidate to determine whether their responses align with their actual performance.

Here are some ideas for questions you can ask:

• What would [candidate name’s] colleagues say about him?

• What is [candidate name’s] biggest achievement at your organization?

• Why did [candidate name] leave your organization?

Keep in mind, however, that you need your applicant’s express consent to conduct a background check – and also that they might not have yet told their previous employer that they’re leaving.

5. Inform unsuccessful applicants and give feedback

When you inform candidates that you haven’t chosen them for the open role, give them feedback based on your findings from the interview and the skills assessment results.

This will help you improve the candidate experience significantly: Most companies still don’t do that, so it’s an easy way to really stand out.

Why should you use skills testing alongside C# data structure interview questions?

If you’ve ever been in a situation where you receive tens or hundreds of applicants to one developer job vacancy, with countless resumes to review, we have good news: You no longer need to do that.

Instead, you can filter candidates with skills tests to see who has the right skills and experience.

Using skills testing before interviews – and instead of resume screening –  is a great way to save time and avoid bias. What’s more, with skills tests you can assess hard and soft skills and even evaluate candidates’ personalities and cognitive ability. 

At TestGorilla, you can choose from three skills tests related to C#: 

• C# (Coding): Data Structures Test

• C# (Coding): Entry-Level Algorithms Test

• C# (Coding): Debugging Test

To assess your candidates’ knowledge of data structure, you can use the first one, which you can combine either with the other two, or with different tests for different skills (up to five in total).

The best way to reduce your workload and put your time to better use is to use pre-employment skills testing, which eliminates unqualified applicants straightaway.

Use skills assessments before  interviews to ensure that all applicants you interview are seasoned developers with the right skills for the role. Interviews also enable you to judge other factors such as culture add or value alignment.

Find an excellent C# developer with the right C# data structure interview questions

Hiring can be difficult, but it doesn’t have to be. Using skills testing can make the recruitment process easier, and the right C# data structure interview questions will help you assess applicants in greater detail.

First, go to TestGorilla to find the most reliable, expert-crafted skills tests to make hiring easy. Build your assessment and start the hiring process now.

Then, once you pre-select your best applicants, you can find your next C# developer with the right C# data structures interview questions from the article above.

The best developers are out there. Now it’s time to find one for your team.  Get started with TestGorilla for free today and start making better hiring decisions, faster and bias-free.