C# Features

This page lists the canonical single-feature guides for the C# section.

Use Versions for release-oriented browsing and Hubs for topic-oriented browsing.

Browse by Topic

Hub	Focus
Null Handling	Null-safe access, nullability, and fallbacks.
Pattern Matching	Pattern families and pattern-driven branching.
Async and Await	Asynchronous methods and async entry points.
String Literals and Interpolation	String formatting and string literal features.
Object Construction and Initialization	Construction, copying, and member initialization.
Collections and Queries	LINQ, projection, slicing, and collection shaping.
Resource Management	Deterministic cleanup and disposal syntax.
Code Organization	File layout, imports, and entry-point structure.
Memory and Performance	Low-allocation and low-level language features.

Canonical Feature Guides

Language fundamentals

Feature	Introduced In	Guide
String interpolation	C# 6.0	Guide
`nameof`	C# 6.0	Guide
Null-coalescing	C# 2.0	Guide
Null-coalescing assignment	C# 8.0	Guide
Null-conditional	C# 6.0	Guide
Null-conditional assignment	C# 14.0	Guide
Nullable value types	C# 2.0	Guide
Nullable reference types	C# 8.0	Guide
`var` implicit typing	C# 3.0	Guide
Dynamic	C# 4.0	Guide
Default literal	C# 7.1	Guide
`nameof` supports unbound generic types	C# 14.0	Guide
Top-level statements	C# 9.0	Guide
File-scoped namespaces	C# 10.0	Guide
Global usings	C# 10.0	Guide
File-based app directives	C# 14.0	Guide
Raw string literals	C# 11.0	Guide
UTF-8 string literals	C# 11.0	Guide
Checked operators	C# 1.0	Guide
Unsigned right shift	C# 11.0	Guide
User-defined compound assignment operators	C# 14.0	Guide
unsafe and fixed	C# 1.0	Guide

Patterns and control flow

Feature	Introduced In	Guide
Pattern matching	C# 7.0	Guide
Constant patterns	C# 7.0	Guide
Property patterns	C# 8.0	Guide
Relational patterns	C# 9.0	Guide
List patterns	C# 11.0	Guide
Switch expressions	C# 8.0	Guide
Out variables	C# 7.0	Guide
Local functions	C# 7.0	Guide
Static local functions	C# 8.0	Guide
Throw expressions	C# 7.0	Guide
break vs continue	C# 1.0	Guide
Discards	C# 7.0	Guide

Objects, types, and initialization

Feature	Introduced In	Guide
Auto-implemented properties	C# 3.0	Guide
Indexers	C# 1.0	Guide
Default interface methods	C# 8.0	Guide
Extension members	C# 14.0	Guide
Field-backed properties	C# 14.0	Guide
Init-only setters	C# 9.0	Guide
Records	C# 9.0	Guide
Target-typed new	C# 9.0	Guide
with expressions	C# 9.0	Guide
Required members	C# 11.0	Guide
Generic attributes	C# 11.0	Guide
Primary constructors	C# 12.0	Guide
Partial constructors	C# 14.0	Guide
Partial events	C# 14.0	Guide
Partial properties	C# 13.0	Guide
Union types	C# 15.0 preview	Guide

Collections, queries, and data shaping

Feature	Introduced In	Guide
Lambda expressions	C# 3.0	Guide
LINQ query expressions	C# 3.0	Guide
Anonymous types	C# 3.0	Guide
Extension methods	C# 3.0	Guide
Lambda parameter modifiers	C# 14.0	Guide
Iterator (`yield`)	C# 2.0	Guide
Tuples	C# 7.0	Guide
Deconstruction	C# 7.0	Guide
Index operator	C# 8.0	Guide
Range operator	C# 8.0	Guide
Collection expressions	C# 12.0	Guide
Collection expression arguments	C# 15.0 preview	Guide
Params collections	C# 13.0	Guide

Async, resource management, and performance

Feature	Introduced In	Guide
async/await	C# 5.0	Guide
async Main	C# 7.1	Guide
using statements	C# 1.0	Guide
Using declarations	C# 8.0	Guide
await using	C# 8.0	Guide
`Span<T>`	C# 7.2	Guide
Implicit Span and ReadOnlySpan conversions	C# 14.0	Guide
ref locals	C# 7.0	Guide
ref returns	C# 7.0	Guide
ref struct	C# 7.2	Guide
readonly struct	C# 7.2	Guide
Generic math	C# 11.0	Guide
Interpolated string handlers	C# 10.0	Guide

Not Included in the Canonical List

Some pages remain in the section as legacy redirects or as design-pattern notes, such as computed properties and lazy properties. They are intentionally excluded from this canonical index because they are not single language-release features.