api: "YAML JSON TOON Database"
version: 1.0.0
format: toon
dataset:
  id: 392
  slug: csharp-dotnet-features
  title: "C# and .NET Modern Features"
  description: "Modern C# features (C# 8-12) and .NET capabilities: nullable reference types, records, pattern matching, LINQ, async streams, minimal APIs."
  category: "Programming Languages"
  category_slug: programming-languages
  tags: "csharp,dotnet,nullable-reference-types,records,pattern-matching,linq,async-streams"
  view_count: 1
  created_at: 1781275786
  updated_at: 1781275786
data:
  features
    [8]{name,version,description,example,notes}:
      "Nullable Reference Types","C# 8.0 / .NET Core 3.0","Compiler warnings for potential NullReferenceException: string? means nullable, string means non-nullable","string? middleName = null; string firstName = middleName ?? \"Unknown\";","Enable with <Nullable>enable</Nullable> in .csproj"
      Records,"C# 9.0 / .NET 5","Immutable reference types with value equality, positional syntax, with-expressions for non-mutating updates","public record Person(string FirstName, string LastName); var p2 = p1 with { LastName = \"Smith\" };","Use record class for reference semantics, record struct for value semantics"
      "Pattern Matching","C# 8-12","Type patterns, property patterns, relational patterns, list patterns for expressive conditional logic","return shape switch { Circle c => c.Radius * c.Radius * Math.PI, Rectangle r => r.Width * r.Height, _ => 0 };","Evolves each version: C# 7 (is/switch), C# 8 (property/recursive), C# 10 (extended), C# 12 (list)"
      LINQ,"C# 3.0 / .NET Framework 3.5","Language Integrated Query: declarative data querying with deferred execution, query syntax and method syntax","var adults = people.Where(p => p.Age >= 18).Select(p => p.Name).OrderBy(n => n);","Works with any IEnumerable<T>; IQueryable<T> for remote execution (EF Core, SQL)"
      "Async Streams","C# 8.0 / .NET Core 3.0","IAsyncEnumerable<T> for asynchronous iteration over sequences, await foreach","await foreach (var item in GetItemsAsync()) { Process(item); }","Essential for paginated APIs, database queries, real-time data streams"
      "Minimal APIs",".NET 6","Simplified HTTP API building without controllers: app.MapGet(\"/\", () => \"Hello\")","var app = WebApplication.Create(args); app.MapGet(\"/todos/{id}\", (int id, TodoDb db) => db.Todos.FindAsync(id));","Reduces boilerplate for small APIs; use for microservices, prototypes, simple backends"
      "Primary Constructors","C# 12 / .NET 8","Constructor parameters directly on class/struct declaration, accessible as instance fields","public class Person(string firstName, string lastName) { public string FullName => $\"{firstName} {lastName}\"; }","Reduces boilerplate; parameters are in scope for the entire class body"
      "Source Generators",".NET 5 / Roslyn 3.8","Compile-time code generation: analyze syntax trees and emit new C# source files","[GenerateSerializer] public class MyData { } // Generates serialization code at compile time","Used by System.Text.Json, EF Core, gRPC; eliminates runtime reflection overhead"