Master Your C# Interview Questions And Get The Job Of Your Dreams

an image of a computer screen with coding on it

Ever since Kanrad Zuse invented Plankalkul back in 1948, we’ve just kept coming up with new ways of telling computers what we want out of them. With each new offering, programmers ask whether they should learn the language. How about C#? Is it smart to master this language and learn those C# interview questions to apply for a job?

a collage of the top programming languages

Image CC, by Daniel Iv​​ersen, via Flickr

C# is one of the more versatile languages out there; in some respects truly multipurpose. It’s easy to work with and will serve you well. It’s great for game building, strikes a balance between simplicity and complexity, and is very scalable. Need some more convincing? We’ve got the lowdown for you, plus tips for how to get that perfect job.

What Is C#?

C sharp programming logo

The first step on your journey to successfully answering C# interview questions (and getting a job, which, let’s face it, is the goal for most of us) is knowing exactly what it is.

What It Does

As with any language, its primary purpose is to define operations in a series so a computer knows how to accomplish a task (and what task you want it to do!) Most of the time, you’ll find people using C# tasks to work with text or with numbers. But in reality, absolutely anything a computer is physically capable of doing you can define and instruct using this language.

Developer: Microsoft

an image on bill gates

Image CC0, via Wikimedia Commons

Microsoft developed and released this language back in 2002. They built it to be similar to Java in order to shorten the learning curve for programmers. It’s a general purpose language that is object-oriented.

Microsoft also went to great lengths to develop a language that would be easy to learn and also…(hold your breath)…fun to use! Naturally, it’s particularly suited for building apps for anything running a Microsoft platform, but it’s also useful if you work with the Unity Game engine and for mobile it can cross platforms.

Learning Curve: Shallow

This is a high-level language, meaning that it reads a bit like the language you actually speak rather than something an alien invented. That makes it simpler to master than some other, more complex languages.

C# is also pretty good at abstracting tasks for you. This fancy term just means it knows a lot of the tasks you want to accomplish and will automate them so you can focus on programming rather than on tedious details.

Scalability: Excellent

What does scalability mean? Scalability in a programming language is a lot different that scalability in a program itself. With a program, scalability means opening it up to massive numbers of users at one time. In a programming language, scalability refers to how you work with it.

Programming is a complex task, and the more threads you can work on simultaneously in your programming, the better. The problems come when you try to bring all those threads together. That’s when the rubber hits the road and you find out whether they different threads are going to interfere with each other or not.

What you want is a programming language that allows clean message passing and multiple threads in real-time that don’t interfere with each other. You get that with C#.

Community Support: Great

team showing support

Image CC0, via Pxhere

With any programming language, the more people that are using it and talking about it, the better it is for everyone. That way we get to share our triumphs, tricks, failures, and even the odd quirks we found by accident. C# has a good user base, and you’ll be able to get plenty of help in the StackOverflow online community and Meetup.com groups. Currently, there are well over 500 Meetup groups talking about C#.

And since the Unity Game engine uses C#, and many people use this for cross-platform development, you’ll find lots of help on Unity forums from people who nailed their C# interview questions and can help you do the same.

How Does C# Compare?

Comparing programming languages is always tricky business. They are, after all, designed to do different things. Some languages are general purpose while others are made for highly specific tasks. There are five types of programming languages, broadly speaking.

Procedural

You’re interested in languages (programming languages, anyway) so maybe you’ve already guessed that procedural means a language tells the computer how to use a specific procedure to solve a problem.

Example: Your mother tells you get her keys out of her purse, go upstairs, use the big key to unlock the secret room, find the third floorboard from the window, pry it up, use the small key to unlock the safe, remove the green file, lock everything back up, and bring it to her. (Surprise, honey! You’re adopted! Here are the papers). You have to do every step of the procedure the way she tells you or the process won’t work.

Functional

This style of programming language is usually contrasted with procedural languages. Functional languages seek to take the minimum number of mathematical expressions and use them to control an infinite number of variations.

Example: Your mother is sad that she had to tell you you’re adopted, so she asks you to use tea leaves, water, and milk to make her some tea. She doesn’t tell you every step along the way, like “get out a pan” and “turn on the faucet,” because you already know the basic “expression” for how to make a liquid boiled mixture.

Want to know more? Check out this explanation from Coding Tech.

Object-Oriented

Now we’re getting somewhere in your quest to nail those C# interview questions. C# is one of the object-oriented languages, though it is also functional. These languages look at the world as objects which have specific characteristics and try to find ways to build new things using these known specifics.

no calorie sweetener packets

Image CC0, via Wikimedia Commons

Example: Your mother forgot to mention she wants sweet tea, so she sends you to the kitchen for sweetener. She can’t remember the name, but she does remember it comes in small, colored, rectangular packets of paper with printing on the outside and something sweet on the inside.

You suggest Splenda, Nutrasweet, Sweet ‘N Low, Truvia…none of those are what she wants. So you design a new type of sweetener, CariesSweet, and put it in a small, colored, rectangular packet of paper with printing on the outside. It’s slightly different, but she knows just what to do with it because it was built on the object model of the others.

Here’s a bit more on the difference between procedural and object-oriented programming:

Scripting

These languages are very specific directions, and while they’re easier to learn than others, they are also very easy to make a mess with. They have elements of both object-oriented and procedural languages. Scripting languages are not often used to build big, complex programs but rather to bear down and give specific instructions to make the most enhanced features run properly.

Example: Your mother has been poisoned by your CariesSweet and needs to go to the hospital. You’ve never driven the car before, so she writes down for you: “Push gas pedal (on right) to go. Push brake pedal (on left) to stop. Turn wheel to steer right or left.”

The rest of the process of getting her to the hospital is already written in your code. You know how to get her up and into the car, how to find your way there, and how to get her out. You interpret her line-by-line instructions in real time as you sit in the car and use it.

Want to understand scripting better? Check out this helpful video.

Logic

These languages let programmers tell a computer to do “if-then” tasks. They don’t really tell computers how to do something. Instead, they tell them the way in which to do something the computer already knows how to do.

doctor shaking with a patient

Image CC0, by Vic, via Flickr

Example: The doctor says your mother will be fine and you should take her home. She tells you to take care of her; but if your mother’s elbow breaks out in bright red spots, call 911 immediately. You already know how to take care of your mother, but the doctor has just told you specifically how to do so “if” something is true.

Languages And How They Compare

Name

Type

Intended Use

Design Goals

C#

Functional, Object-Oriented

Applications

Make applications 
quickly

BASIC

Procedural

Education

Simplicity

Java

Object-Oriented

Application

Write it once and use it everywhere

JavaScript

Object-Oriented,
Functional

Web scripting

Easily Accessible

PHP

Object-Oriented

Web Application and CLI

Robust and simple to 
use

Fortran

Procedural
(mainly)

Scientific 
Applications

Efficient runtime and 
simple syntax

Pascal

Procedural

General 
Applications

Readable, Modular, 
Disciplined

Jobs Where C# Is Used

Is it worth it learning C# interview questions and how to answer them? Is working with C# a good career choice? Let’s see:

What Can You Do With It?

C# is a great all-around tool for a software developer to have under their belt. With it, you can design web applications, work on mobile applications across platforms, and also make desktop apps for Windows. You can also design games with C#. You can work with Android or iOS, apps or games, websites or desktop clients. That’s a lot of variety, and if you can master those C# interview questions, all kinds of doors will open for you.

mobile phones

Image CC0, by Bhautik Joshi, via Flickr

As a C# developer, you can work in development, tech support, or green field development. You can design, troubleshoot, or test. You can work in big finance companies, major corporations, or directly in software development.

Which Companies Use It?

Here’s the great part: all kinds. This doesn’t mean every company uses C#; it means every TYPE of company uses it. If you want to work for a startup, you can find one easily.

company logos

Image via StackS​​hare

If you prefer working for a giant corporate conglomerate where no one knows your name (but you get in-house yoga), you can easily find a demand for C# from these guys. If you want to set out on your own and work freelance, you can step into all kinds of roles with a background in C#.

What About Job Security?

Because such a wide variety of companies are using C#, your prospects in learning this language are very solid. One of the most encouraging signs is that a lot of the bigger financing corporations are choosing to use it; that means there are high-salary jobs in play here.

C# is also used worldwide, so if you don’t love where you live you can move along. Don’t forget that you can always specialize in a niche market as it gets hot: but you want to have a solid foundation to fall back on when today’s fad is tomorrow’s trash. C# can be that solid foundation, and that’s reason enough to learn how to nail those C# interview questions.

OK, But What About Other Programs?

You’ve only got so much time, and you aren’t sure whether to work on C# interview questions, learn Java, concentrate on Ruby, or go with Javascript. You’re thinking: we like that. Let’s hash it all out, shall we?

Java

javascript

So this language is quite similar to C#, and if you’re just breaking into the programming world you might be tempted to spring in this direction just because the name is so famous.

Learning Java is NOT a bad career decision. Let’s just get that out to the way. Also, we have to admit that Java might give you better support if you’re working with big data frameworks. However, it falls down when you’re talking about building desktop clients.

Not only that, but Java features are starting to fall behind C#. It’s been a big player for a long time, but that’s slowly changing. If you’re just starting out, C# might be your VHS and Java your Betamax. That’s a bold claim, but consider this: Nothing works like the C languages when it comes to IoT devices and wearables. The future is smart tech, and that means C is likely to expand.

Javascript

image of javascript coding on a screen

Image CC0, by Christiaan Colen, via Flickr

This one is in very high demand right now, and it’s easy to learn. React Native lets you use it for mobile apps, and you can do desktop with Electron in Javascript.

However, it’s clunky. It wasn’t meant to work with enormous codebases, and after a while you’ll get tired of doing the front-end framework over and over again, reinventing the wheel each time.

It doesn’t hurt to have some exposure to Javascript, but our advice is to put this in the secondary priority category in favor of C#. Javascript is not being used to build the most popular modern software and eventually there won’t be much legacy software that needs it.

Ruby

a red clip art ruby for the ruby programming company logo

Image CC0, via Wikimedia Commons

Ruby has some good things going for it, and if you want to work remotely there are typically more jobs available in Ruby than in C#. But even the most die-hard Ruby devotee will usually admit that you get better overall performance out of C#.

C# allows you to do static typing, which saves you time and allows you to refactor a lot more quickly. Again, there’s nothing wrong with moving to Ruby, but you’re likely to get more out of your C# training.

Programming Language Popularity Trends

Top Languages in 2018

top languages chart

If the numbers in those don’t seem too impressive, consider this: Back in 2002, C# was in the #11 spot of most popular languages. Java, meanwhile, has been #1 for a long time, but has recently slipped to third place.

Getting Your C# Job

One of the draws of programming as a career is that you don’t necessarily need a degree in order to succeed. You do, however, need training. Here’s what to do:

Learn Your Language

Start with the basics, right? Get some books, take some classes, and get familiar with C# so you have some hope of answering C# interview questions.

Get Experience

image of a guy at a restaurant coding in a booth on his computer

Image CC0, by Roland Tanglao, via Flickr

In any job, this is the Catch 22. You have to have
experience to get a job, and you have to have a job to get experience. So what do you do? Here’s some advice:

  1. Develop a great, complex project. Put this up on Github so you can send a link with your resume.
  2. Develop a few smaller projects to go with it. Just remember that it’s better to have fewer perfect projects than a whole lot of mediocre ones.
  3. Contribute to some open source projects. This will beef up your resume and present you as a helpful and established member of the coding community.

Learn about how to use Github here. 

How To Get Ready For An Interview

When you get a job, no matter what area you want to work in, you have to present yourself the right way. No matter how amazing your coding skills are or how well you answer C# interview questions, if you don’t come across as someone a company actually wants to hire you’re not going to get the job.

Decide What You Want

decisions whats in your future wording display

Image CC0, via 477th Fighter Group

Are you interested in working with software? Web development? In-house or freelance? Big company or small startup? Decide what you’d like to do, as well as what you’re willing to do (because we don’t always get what we want), and then move on to step two.

Do Some Research

You know what companies like? Job applicants that know something about the company and want to work there. If you do some research on the company and the position, you show that you’re organized and motivated. You show that you are capable of learning. You show that you’ll fit into the corporate culture of the place you’re looking to land.

Build Your Resume and Portfolio

clipart photo of woman taking resumes

We tech people tend to minimize the value of a good resume. We figure our work will speak for itself. We figure that if we can answer the C# interview questions well, we’ll be all set.

That’s partially true, but it’s not the whole story. You have to get your foot in the door so someone will ask you those C# questions, and nothing will get you in there faster than a good resume. This is especially true if you’re looking to work for something like a finance company or a university rather than directly for a software development company.

How should you do your resume? Here are some tips:

KEEP IT SIMPLE

Fancy colors and complicated layouts aren’t going to get you noticed. They’re going to get you overlooked. Keep your fonts big enough to read but not so big it looks like a preschool project. 10-12pt is the right size.

BE EASY TO FIND

Your contact info needs to be correct and clear. If you’re still using your high school email, [email protected], or you have a weird nerd handle like hackslash1995, get a professional email address right now.

START WITH A CLEAR OBJECTIVE

If someone picks up your resume, this is one part they definitely will read. This isn’t the place to be funny or sarcastic. Be clear, direct, and simple. Feel free to adjust it to show you can meet your employer’s needs.

SHOW EDUCATION AND EXPERIENCE CLEARLY

Use active verbs to describe what you’ve done. Avoid phrases like “I was in charge of…” and stick with things like “Developed a flight simulator…”

DON’T INCLUDE IRRELEVANCIES

Your mom is mighty proud of your spelling bee tournament win, but this doesn’t matter to your prospective employer. Keep things relevant unless they show mastery of a soft skill that is useful on the job. If you successfully led a team, for example, flag that up.

USE NUMBERS WHERE YOU CAN

Numbers are specific. Did you increase profits? By how much? Did you make something work more efficiently? How much more efficiently?

DON’T ADD YOUR PICTURE

Unless you’re applying for a job as a model, no one needs to see your face before an interview. If they do, you probably don’t want to work for them anyway.

Practice for the Real Thing

Once you line up an interview, you need to buckle down and prepare. It’s not enough that you can nail those C# interview questions: you also have to be able to present well with everything else.

Keep Your Brain Coding

Practice what you’ll be asked and practice your coding skills. Brush up on chapters of your training books that you haven’t dealt with in a while. Make sure your brain is knee-deep in the specifics of coding before you set out.

Do a Mock Interview

You don’t have to do a bunch of these: just one or two is fine. Make sure you get help from a friend who actually does interviews rather than from your mom or Don your drinking buddy.

Practice Non-Tech Skills

So you can code beautifully: that’s great! But if the interviewer asks you to talk about yourself, your previous experience on a team, what motivates you, or how you have learned from previous experience, you need to be able to give competent answers to these questions.

What Not to Do

Yup. There are some things you should definitely avoid when preparing for the interview.

TRY TO LEARN A NEW LANGUAGE

No, you can’t master Python by next week. It’s much better to be a virtual C# ninja and impress them with your answers to C# interview questions than to be able to “sort of code” in three languages.

SKIP SLEEP

Yes, you want to bone up on skills. But remember how not sleeping didn’t really help you in your high school exams? You’re even older now, and skipping sleep will not help even more than it didn’t help before. (Don’t show your high school English teacher that last sentence).

FORGET TO FOCUS ON THE COMPANY

Tailor everything about your interview prep to the specific job and the specific company you’re going to be talking to.

BURN OUT

After an hour or so, give yourself a break. Target your strengths rather than try to learn new stuff. And don’t jump around like a frantic frightened rabbit from book to book and website to website. There’s too much out there. Instead, concentrate on a few good resources of C# interview questions.

INVEST YOUR SELF-WORTH IN ONE INTERVIEW

There will be more. You will get a job. Sometimes people don’t get jobs, not because they’re stupid or unworthy, but just because they didn’t. If you don’t get this job, don’t let it throw you into a funk.

Show Up Looking Professional

By professional, we do not necessarily mean you have to wear a suit. Lots of tech companies are super casual. The way to do an interview right is to find out what the company wears to work and wear something one step smarter. If everyone wears suits, though, stick with a suit: suits are the most formal of business wear.

Just make sure it fits. A suit that doesn’t fit tells your employer you’re not very self-aware. If everyone is casual, you go casual, but make it smart casual, not “ripped-jeans-with-wife-beater” casual.

Here are a few more tips to bear in mind:

  • Never wear a t-shirt to an interview: even the company t-shirt
  • Never wear dirty clothes
  • Never wear clothes with wrinkles
  • Never wear brightly colored socks
  • Men, here are your tips for getting the dress right.

    Women, here’s what you need to know to get the job.

    Practice Your C# Interview Questions

    There are a lot of possible questions that could come up, but here are 10 you should definitely master:

    1. What Will the Following Code Snippet Output?

    using System;
    public class Program
    {
    public static void Main(string[] args)
    {
    Console.WriteLine(Math.Round(6.5));
    Console.WriteLine(Math.Round(11.5));
    }
    }

     6 12

    2. What Will the Following Code Snippet Output?

    using System;
    public class Program
    {
    public static void Main(string[] args)
    {
    byte
    num = 100;
    dynamic val = num;
    Console.WriteLine(val.GetType());
    val += 100;
    Console.WriteLine(val.GetType());
    }
    }

    System.Byte
    System.Byte

    3. What Will the Following Code Snippet Output?

    using System;
    using System.Collections.Generic;
    namespace
    TechBeamers
    {
    delegate string del(string str);
    class sample
    {
    public static string DelegateSample(string a)
    {
    return a.Replace(‘,’, ‘*’);
    }
    }
    public class InterviewProgram
    {
    public static void Main(string[] args)
    {
    del str1 = new del(sample.DelegateSample);
    string str = str1(“Try,,CariesSweet,,not,,Poison”);
    Console.WriteLine(str);
    }
    }
    }

    Try**CariesSweet**not**Poison

    4. Describe Dependency Injection

    Dependency injection unlinks classes so they are no longer directly dependent on one another. There are three ways to do this in C#: method, property, or constructor dependency.

    5. You Have a Word String with $ Symbols, Like: “My Mother Drinks $ Tea $ with Sweetener $” How Do You Remove the Second and Third $ from This String?

    Use an expression like:

    string s = “like for example $ you don’t have $ network $ access”;
    Regex rgx = new Regex(“\$\s+”);
    s = Regex.Replace(s, @”($s+.*?)$s+”, “$1$$”);
    Console.WriteLine(“string is: {0}”,s);

    6. Can You Store Mixed Datatypes in One Array? How?

    Yes, because an array can be an object storing any datatype and class object. Here’s an example:

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;

    namespace ConsoleApplication8
    {
    class Program
    {
    class Customer
    {
    public int ID { get; set; }
    public string Name { get; set; }
    public override string ToString()
    {
    return this.Name;
    }
    }
    static void Main(string[] args)
    {
    object[] array = new object[3];
    array[0] = 101;
    array[1] = “C#”;
    Customer c = new Customer();
    c.ID = 55;
    c.Name = “Manish”;
    array[2] = c;
    foreach (object obj in array)
    {
    Console.WriteLine(obj);
    }
    Console.ReadLine();
    }
    }
    }

    7. What Will the Following Code Snippet Output?

    class Program {
    static String location;
    static DateTime time;

    static void Main() {
    Console.WriteLine(location == null ? “location is null” : location);
    Console.WriteLine(time == null ? “time is null” : time.ToString());
    }
    }

    location is null
    1/1/0001 12:00:00 AM

    8. Is This a Valid Comparison? Explain

    static DateTime time;
    /* … */
    if (time == null)
    {
    /* do something */
    }

    is is allowed by the compiler, but it could lead to bugs. The == will try to get a common type on both sides so it can compare, and you will get the expected result. However, you might also get some unexpected behavior, and though valid, the result is false.

    9. What Is the Algorithm to Check If a Number Is Prime?

    /*
    * C# Program to Check Whether the Given Number is a Prime number if so then
    * Display its Largest Factor
    */
    using System;
    namespace example
    {
    class prime
    {
    public static void Main()
    {
    Console.Write(“Enter a Number :
    “);
    int num;
    num = Convert.ToInt32(Console.ReadLine());
    int k;
    k = 0;
    for (int i = 1; i <= num/2; i++)
    {
    if (num % i == 0)
    {
    k++;
    }
    }
    if (k == 2)
    {
    Console.WriteLine(“Entered Number is a Prime Number and the Largest Factor is {0}”,num);
    }
    else
    {
    Console.WriteLine(“Not a Prime Number”);
    }
    Console.ReadLine();
    }
    }
    }

    10. How Do You Check Whether a Number Is an Armstrong Number?

    /*
    * C# Program to Check Whether the Entered Number is an Armstrong Number or Not
    */
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;

    namespace ConsoleApplication6
    {
    class Program
    {
    static void Main(string[] args)
    {
    int number, remainder, sum = 0;
    Console.Write(“enter the Number”);
    number = int.Parse(Console.ReadLine());
    for (int i = number; i > 0; i = i / 10)
    {
    remainder = i % 10;
    sum = sum + remainder*remainder*remainder;

    }
    if (sum == number)
    {
    Console.Write(“Entered Number is an Armstrong Number”);
    }
    else
    Console.Write(“Entered Number is not an Armstrong Number”);
    Console.ReadLine();
    }
    }
    }

    You can find plenty more example questions that appear frequently in C# interviews by checking out this video.

    After The Interview

    Here’s what to do once you’re done:

    Write Down the Experience

    Record what you were asked, how you answered, and questions you wished you’d asked and didn’t. This could be very helpful in follow-up interviews or interviews with another company.

    Know What to Expect

    If they said they would be in touch within 10 days, then wait 10 days and then reach out with a quick email to the hiring manager. Make it polite and short.

    Talk to Your References

    If a company might be contacting someone on your reference list, give that person a heads up just in case.

    Prepare for Salary Negotiations

    Make sure you know the average salary for the position generally, but specifically for your region. The more experience you have, the more you can ask for: you’ll need around five years experience for it to make a difference.

    Ask for a bit more than you want so you can fall back to your desired salary; but don’t oversell or undersell yourself.

    Getting Your Dream Job

    Whether you want to work for a big tech company or do things entirely on your own terms. C# is a way to get there. Prepare yourself for the interview, nail those C# interview questions, and follow up sensibly. You’ll be surprised what a difference some preparation can make.

    business man relaxing in chair