The best new features of C# 14

C# 14, shipping with .NET 10, introduces several notable features. File-based apps let you run a single .cs file directly from the command line without a project or solution file. Extension members add a new block syntax for declaring both extension methods and extension properties, allowing cleaner grouping by receiver. The nameof operator now supports unbound generic types like List<> and Dictionary<,>, eliminating the need for dummy type arguments. User-defined compound assignment operators (+=, -=, *=, etc.) can now be overloaded directly on custom types, enabling cleaner, more readable code.