What’s New in .NET 9 & C# 13

Explore C# 13 indexers that accept barams, enabling dynamic multi-key lookups and spreadsheet-style references without overloads. Build a magic table that works with any type and demonstrates cache keys.

Explore C# 13 partial properties in .NET 9, enabling splitting property logic across files with a generated class and backing field, validation to keep API clients and DTO rules modular.

Protect a shared counter with typed lock objects to ensure thread-safe increments. A private lock type prevents wrong values and yields a deterministic output of 1000 under multi-threaded access.

Explore C# 13 foreach with ref readonly loops, which reduces copying of large structs, boosts performance, and lowers allocations, shown with the performance profiler and object allocation tracking for games.

Discover the official escape sequence in C# 13 for escaping characters, replacing old methods with a concise syntax, and see ANSI escape codes for color output in terminals.

C# 13 improves delegate type inference, letting logMessage assign to action or func without casts, reducing friction and keeping ABI clean in event wiring.

Explore ref fields in readonly structs in c# 13, enabling read-only references inside immutable structs for high-performance memory access, while preserving immutability in performance-critical code.

Explore how using alias directives simplifies complex type names in C# 13, enabling any type expression and creating readable aliases for user data, dictionaries, or arrays to improve maintainability.

Explore how C# 13 optional parameters gain broader default values and better support for named arguments in the .NET 9 landscape, reducing overloads and simplifying method calls.

Explore dynamic profile guided optimization in .NET 9, where the JIT reoptimizes hot methods at runtime with inlining, loop unrolling, and constant folding, boosting performance without redeploying.

Discover how DUTNET 9 improves garbage collection with smarter memory handling, faster background memory compaction, and adaptive gen 2 collections using DUTNET Trace.

Upgrade to .NET 9 to boost async performance with faster state machines and reduced allocations. Improve pooling and lower boxing to raise throughput for APIs and IO-bound tasks without changes.

Explore .NET 9's new vector and matrix apis for high-performance math with no extra libraries, using vector2 and vector3. Apply rotation, translation, and projection as one-liners with hardware acceleration.

Aot 2.0 in .NET 9 speeds cold starts to 120 ms on low-end hardware, with smarter linking and trimming reducing file size and load time for serverless and low-power devices.

In .NET 9, UTF-8 becomes first-class, enabling native UTF-8 strings and direct handling in protocols, file formats, and web interfaces; enjoy faster performance, smaller allocations, and broader UTF-8 parsing.

Explore time abstraction APIs in .NET 9 with time provider to control time. Swap real or fake providers for testing, enabling validation of expirations, scheduling, and rate limits.

Boost file i/o in .NET 9 with faster async reads and writes, smarter pipelines, and fewer memory allocations, enabling efficient streaming for large data.

Accelerate routing in ASP.NET Core 9 with faster matching, improved tree-based routing, and better caching, supporting optional trailing slash patterns and upgrades from .NET 8 for MVC and minimal APIs.

Explore http/3 with quic in .NET 9, enabling faster connections, reduced cpu usage under load, and better alpn negotiation via the Kestrel server.

Explore the upgraded model binding and validation in asp.net core, featuring a faster json binder that streams data on the fly and supports binding to read only memory bytes.

Explore output caching 2.0 in .NET 9, caching by query strings, headers, or custom logic, configure with addoutputcache, apply policy names for centralized, reusable rules, and improve performance.

Enable optional deflate compression for large websocket messages in .NET 9 and C# 13 to reduce network usage, with reduced allocations and faster frame barcing under high concurrency.

Enable automatic CSRF protection with the new antiforgery middleware, generating and validating tokens by default for unsafe methods, while allowing header, cookie, and error customization for rapid, zero-config security.