C# documentation

Learn to program in C#

Get Started

• Online, interactive Hello world
• Math and numbers in C#
• Introductory tutorials
• Create C# apps with Visual Studio

video

• What is C#?
• C# 101 video series

Download

• Download the .NET SDK

C# fundamentals

Overview

• A tour of C#
• Inside a C# program
• Main() and command-line arguments

Concept

• The C# and .NET type system
• Language Integrated Query (LINQ)
• async and await

Tutorial

• Object-oriented inheritance
• Use LINQ to query data
• Format text using string interpolation
• Browse all tutorials

New features in C# 9.0

What's new

• What's new in C# 9.0

New features in C# 8.0

What's new

• What's new in C# 8.0

Overview

• Pattern matching
• Nullable reference types

Concept

• Choose a nullable migration strategy

Tutorial

• Consume and generate async streams
• Develop with nullable reference types
• Upgrade existing code to use nullable reference types
• Use pattern matching for more expressive algorithms
• Safely version interfaces with default interface members
• Mix in functionality with default interface members
• Work with subsets using ranges and indices

Reference

• Breaking changes in the C# compiler

C# language reference

Reference

• Language reference
• C# keywords
• C# operators
• Configure language version
• C# language specification