Learn C#
A free, interactive online C# course. You write C# on every lesson, with real C# code examples, AI hints when you're stuck, and a free certificate of completion when you finish.
136,192+ codders enrolled
205 lessons198 challenges1,291 quiz questions
- Beginner friendly
AI-assisted coding help
Hands-on interactive lessons
Audio narration on every lesson
Quizzes to test your knowledge
Free certificate of completion
Syllabus
Section 1
Fundamentals
Start sectionStartBuild a strong foundation with essential concepts and basic skillsIntroduction
4 lessons322Variables Part 1
5 lessons539Variables Part 2
5 lessons431Operators Part 1
5 lessons438Operators Part 2
5 lessons531Decision Making
6 lessons638Basic IO
6 lessons633Calculator App
Project4 lessons4Loops
8 lessons751Methods (Functions)
6 lessons641Arrays Basics
6 lessons629String Operations
3 lessons324Iterating Over Collections
3 lessons323Final Challenges
3 lessons38Section 2
Logic & Flow
Start sectionStartMaster advanced C# programming with a focus on data structures and flow control. Learn to work with complex arrays, collections, error handling, and time management.Multi-dimensional Arrays
7 lessons750Advanced Decision Making
5 lessons932Loop Enhancements
5 lessons632Flow Control Techniques
5 lessons937Exception Handling
8 lessons1160Null Handling
5 lessons832Logical Operators Advanced
4 lessons723Data Analysis System
Project6 lessons6HashMap Part 1
6 lessons536HashMap Part 2
4 lessons415HashSet Part 1
6 lessons537HashSet Part 2
5 lessons539Section 3
Object Oriented Programming
Start sectionStartDiscover how to organize code with classes, objects, and reusable structuresFundamentals of OOP
9 lessons1772Properties & Static Members
5 lessons945Class Architecture
4 lessons427Inheritance
6 lessons644Polymorphism & Interfaces
6 lessons644Encapsulation
5 lessons535Advanced Features
5 lessons535Advanced OOP Concepts
6 lessons652Variable Arguments
4 lessons436Design Patterns Part 1
5 lessons545Design Patterns Part 2
6 lessons655Project: Library System
6 lessons6Final Challenges
3 lessons3
C# courses
Hands-on C# courses, free to start in your browser.
Beginner Challenges - Practice Basic Concepts
PopularPut your beginner coding knowledge to test and try to solve this programming challenges, use any language you want, Happy Coding!
Certificate on completion
- 20
- 20
Coding Problems
PopularPut your programming problem solving skills to the test using the exercises with different difficulties in this course. Designed for coders with some prior knowledge of the basic syntax in any programming language.
Certificate on completion
- 32
- 31
Stack - Data Structures Series #1
In this course, you will learn about the Stack data structure, create a Stack from zero using your preferred language, and practice coding challenges with it!
- 13
- 11
- 1
AVL Tree - Data Structures Series #10
In this course, you will learn about the AVL Tree data structure, build a self-balancing binary search tree from zero in your preferred language, and practice coding challenges with it!
Certificate on completion
- 16
- 14
- 1
Linked List - Data Structures Series #5
In this course, you will learn about the Linked List data structure, create a Linked List from zero using your preferred language, and practice coding challenges with it!
Certificate on completion
- 14
- 12
- 1
Binary Tree - Data Structures Series #3
In this course, you will learn about the Binary Tree data structure, create a Binary Tree from zero using your preferred language, and practice coding challenges with it!
- 13
- 11
- 1
Learn by Doing
Write real code, query databases, build websites, and master AI prompts. Our interactive lessons cover every skill modern developers need.
Build Your Streak
Stay consistent and watch your progress grow! Track your daily coding habit, protect your streak with freeze days, and earn rewards for showing up every day.
12 days streak
Return tomorrow to keep your streak!
January 2026
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Double or Nothing
Day 5 of 7
Streak Freeze
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Code Anywhere
Take your coding journey on the go! No setup, no downloads: just open and start coding. Available on iOS, Android and Web with 4.9 star ratings.
You're Not Alone
Compete on global leaderboards, invite friends to earn rewards, and celebrate each other's wins. Coding is better with friends!
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Promotion zoneEvery way to learn
Read, listen, test yourself, ask the AI, or look up anything you've already covered. Every lesson meets you where you are.
A variable is a named container that stores a value you can reference later in your program.
In Python, you create one by writing the name, an equals sign, then the value you want to store.
The value can change over time. Reassigning the name simply points it to a new value.
Earn a Certificate
Earn certificates for every course you complete. Add them to your LinkedIn profile and resume to showcase your coding expertise to employers.
Certificate of CompletionPython Fundamentals
Add to LinkedInWhy learn C# with Coddy
- Write and run real C# code in your browser. No Visual Studio install, no .NET SDK setup. Each lesson compiles your C# program server-side and shows the output instantly.
- Object-oriented C# the way it's used in production: classes, properties, inheritance, interfaces, generics, exception handling, LINQ. Code examples and exercises after every concept.
- AI hints help you debug C# code and read compiler errors so the language feels approachable instead of intimidating, especially if you're new to OOP.
- Free C# certificate of completion when you finish. Useful for game-dev (Unity), backend, and enterprise roles where C# fluency is a baseline expectation.
Frequently asked questions about learning C#
Is C# hard to learn?
C# is one of the more approachable strongly-typed languages. The syntax is consistent, the standard library is large and well-documented, and modern features like properties and pattern matching cut down on boilerplate. Most beginners get their first C# program running within the first hour and reach classes and inheritance within a week.
How long does it take to learn C#?
C# basics - syntax, methods, classes, objects - take two to four weeks of daily practice. Comfortable use of inheritance, interfaces, generics, and LINQ usually takes one to three months. Going deeper into ASP.NET, Unity game development, or enterprise patterns is a separate ramp.
What's the difference between C# and Java?
C# and Java are close cousins. Both are strongly-typed, class-based, garbage-collected. C# tends to adopt new features faster (properties, LINQ, async/await, pattern matching) and is heavily used for Unity game development and Windows tooling. Java leans more toward Android and large enterprise backends. The skills transfer in both directions.
Can I use C# for game development?
Can I learn C# online for free?
Yes. The interactive C# course is free - lessons, coding exercises, quizzes, and a certificate. The editor runs in your browser so you don't need to install Visual Studio, the .NET SDK, or any IDE to start writing C#.
Do I get a C# certificate after the course?
Yes. Finishing the C# course gives you a free certificate of completion you can add to your resume or share on LinkedIn - a verifiable signal alongside any Unity projects, .NET apps, or GitHub repos you've built.
