Let’s catch up with C#! Exciting new features in C# 9, 10, 11, 12 and 13!

on YouTube ↗59m

" summary

Covers concrete language changes: how nullable reference types plus compiler null-state analysis and the required modifier catch real NRE risks, and how record types, init-only, target-typed new and value-based equality replace boilerplate. Shows pattern matching, list/span/slice patterns and switch expressions, UTF8/raw string literals and zero-allocation slicing with ReadOnlySpan, collection expressions with the spread element, primary constructors, the new lock type, and field/implicit-span/nullable-assignment changes coming in C# 13–14.

AI-written summary · about

" chapters (10)

1. 0:00Introduction to C# evolution
2. 3:09Nullable reference types
3. 11:57C# 9 new features
4. 17:02Pattern matching advancements
5. 24:13C# 10 features
6. 28:06C# 11 features
7. 30:12Language performance and security
8. 34:43Advanced patterns and interfaces
9. 41:50C# 12 and 13 highlights
10. 48:09Future C# developments

" related talks

• 59mLet’s catch up with C#! Exciting new features in C# 9, 10, 11, 12 and 13!Filip Ekberg · NDC Copenhagen 2025
• 55mLet’s catch up with C#! Exciting new features in C# 9, 10, 11 and 12!Filip Ekberg · CPH DevFest 2024
• 59mWhat's new in C#? Exciting new features in C# 9, 10 and 11!Filip Ekberg · Copenhagen Developers Festival 2023
• 01h 00mWhat's new in C#? - Exciting new features in C# 9, 10 and 11!Filip Ekberg · NDC Oslo 2023
• 01h 03mWhat's new in C#? Exciting new features in C# 8.0, 9.0 and 10!Filip Ekberg · NDC Porto 2022
• 01h 00mWhat's new in C#? Exciting new features in C# 8.0, 9.0 and 10!Filip Ekberg · NDC Oslo 2022
• 59mWhat's new in C#? Exciting new features in C# 8.0, 9.0 and 10!Filip Ekberg · NDC Sydney 2022
• 41mWhat's New in C# 9Andrey Dyatlov · DotFest 2020