C# and .NET Online Test

TestDome skill assessments are used by more than 11,000 companies and 1,030,000 test takers.

For Jobseekers

Practice your skills and earn a certificate of achievement when you score in the top 25%.

Take a Practice Test

For Companies

Test candidates with real-world problems and interview the best ones.

Sign Up to Offer this Test

About the test

The C# and .NET online test assesses knowledge of the .NET framework and its class library. This test includes live coding tasks in the C# programming language as it is the most used language for .NET.

The assessment includes work-sample tasks such as:

  • Working with classes, objects, and interfaces to write reusable code.
  • Implementing and properly using algorithms and data structures to optimize application performance.
  • Using the Async-Await pattern to work with asynchronous code.

A good .NET developer needs a solid understanding of the C# programming language and the .NET framework class library in order to write robust and maintainable code.

Sample public questions

20 min

Your company is analyzing malware which targets numerical record files.

The malware uses a sliding window over the array of numbers in a file, and tries to match the following pattern:

Tl, -, -, X, -, -, -, Tr

The entire window is moved so that 'X' passes through all the values and is compared to the numbers at the 'Tl' and 'Tr' locations, which are positioned at a constant offset to 'X'.

The malware has the following rules:

  • If the value at the 'Tl' or 'Tr' position of the pattern is bigger or equal to the value at the 'X’ position, the malware replaces the value at 'X' with 0.
  • If the value at the 'Tl' or 'Tr' offset is out of bounds, then the value at 'X' is only compared to the other existing value.
  • The record is processed in two stages: first, all the positions that should be set to 0 are located, using the original values for comparison. Only after all positions have been identified do they get set to 0.

For example, if the values in a record file are the following:

new int[] { 1, 2, 0, 5, 0, 2, 4, 3, 3, 3 }

The expected values after the malware runs are:

new int[] { 1, 0, 0, 5, 0, 0, 0, 3, 3, 0 }

In this example, both '2's, the '4' and the last '3' were replaced by 0.

Implement the Simulate method so that the malware behavior is replicated for further study.

5 min

Consider the following code:


public class RecyclingBin
    protected List<string> recyclables = new List<string>();
    public void Add(string recyclable)
        if (recyclable.Split(' ').Length > 1 && recyclable.Split(' ')[1].Length > 3)
    public List<IGrouping<string, string>> SortRecyclables()
        return recyclables.GroupBy(recyclable => recyclable.Split(' ').First()).ToList();


Public Class RecyclingBin
    Protected recyclables As List(Of String) = New List(Of String)
    Public Sub Add(recyclable As String)
        If recyclable.Split(" ").Length > 1 And recyclable.Split(" ")[1].Length > 3
        End If
    End Sub

    Public Function SortRecyclables()
        Return recyclables.GroupBy(Function(recyclable) recyclable.Split(" ").First()).ToList()
    End Function
End Class

Select the statements that are true if a new RecyclingBin is instantiated and the Add method is called with the following recyclable parameters: "metal pipe", "plastic toy", "metal bar", "copper wire", "plastic button", "wire", and "brass".

For jobseekers: get certified

Earn a free certificate by achieving top 25% on the C# and .NET test with public questions.

Take a Certification Test

Sample silver certificate

Sunshine Caprio

Java and SQL
TestDome logo icon

For companies: premium questions

Buy TestDome to access premium questions that can't be practiced.
Get money back if you find any premium question answered online.

Sign Up to Offer this Test

81 more premium C# and .NET questions

Enum, String, NET Versions, Order Chars, Max Sum, Integer to Object, Product Refactoring, Sort Params, Sum of Numbers, Delayed Print, Third Party Components, String Operations, Racer, Read First Line, Prefix, Chinese Box, Car Rental, Eye of the Storm, Document Store, Snapshot, Moving Total, Driver Exam, Classroom, Username, Weighted Average, Kilometer Converter, Document Counter, Disposable Wrapper, Platformer, String Occurrence, Hobbies, Language Teacher, Read Write Execute, Node, Friend, Internal Nodes, Crop Ratio, Unique Numbers, Wheel Defects, Log Parser, Shelf Test, Chain Link, Worker, Veterinarian, Window Manager, Ceramic Store, Stories, Paper Strip, Segment, Procedural Generator, Flight Connections, Nullable Employee, Citizen Income, Vectors, Date Transform, Book Sale, Blog Posts, Construction Game, Calories Burned, XML Navigation, Shipping, Memory Leak, Gearbox, Planet Search, Company Stock, Digital Flasks, Airport Networks, Patient Class, Patient Class, Unique Product, Ingredient Tuple, Stack to List, Log Patch, Circuit Simulator, Fire Dragon, Shining Star, Chemical Machine, Bicycle, Flimsy Ladder, Paragraph, Animal Hierarchy.

Skills and topics tested

  • .NET
  • Enum
  • Class Library
  • CLR
  • LINQ
  • C#
  • Algorithmic Thinking
  • Boxing and Unboxing
  • Memory Management
  • Accessibility Levels
  • OOP
  • Refactoring
  • Pass by Reference
  • Async-Await
  • Multithreading
  • Package Manager
  • StringBuilder
  • Synchronization
  • Exceptions
  • Data Structures
  • Sorting
  • Bug Fixing
  • Language
  • Lists
  • HashSet
  • Properties
  • Regex
  • Strings
  • Arithmetic
  • Inheritance
  • Method Overriding
  • Destructors
  • Linked List
  • Stream
  • Dictionary
  • Iteration
  • Recursion
  • Tree
  • Graphs
  • Arrays
  • Integer Division
  • Serialization
  • XML
  • Test Case Design
  • Unit Testing
  • Queue
  • Dynamic Programming
  • Random
  • Null Coalescing Operator
  • Null Conditional Operator
  • Entity Framework
  • Eager Loading
  • Lazy Loading
  • Dynamic Objects
  • Conditions
  • AI Code Review
  • Conditional Statements
  • Loops
  • 2D Array
  • Abstract Class
  • Tuples
  • Complexity
  • Stack
  • Extension Methods
  • Higher Order Function
  • Interfaces
  • TDD
  • Field Modifiers

For job roles

  • .NET Developer
  • Back-End Developer
  • C# Developer
  • Web Developer

Sample candidate report

What others say

Decorative quote

Simple, straight-forward technical testing

TestDome is simple, provides a reasonable (though not extensive) battery of tests to choose from, and doesn't take the candidate an inordinate amount of time. It also simulates working pressure with the time limits.

Jan Opperman, Grindrod Bank

Product reviews

G2 - Crowd Badge
G2 - High Performer (2022)
Capterra - 4.5 Stars
Capterra - Shortlist (2023)

Used by

Solve all your skill testing needs

150+ Pre-made tests

From web development and database administration to project management and customer support. See all pre-made tests.

90+ skills

From JavaScript and SQL to English and customer support. See all questions to filter by skill.

Multi-skills Test

Mix questions for different skills or even custom questions in one test. See an example.

How TestDome works


Choose a pre-made test
or create a custom test


Invite candidates via
email, URL, or your ATS


Candidates take
a test remotely


Sort candidates and
get individual reports

Want to know more?

Related C# and .NET Tests: