What are union types in C# 15?

Union types let a var hold one of a fixed set of types, like string | int, with compile-time checks via switch.

How do I try C# 15 union types in .NET 11?

Download .NET 11 Preview 2 SDK, use net11.0 target framework, VS 2026 Insider. Switch on a union var — compiler guides you.

For known types, yes — safer, explicit. object stays for true dynamics.

🚀 New Releases

Why settle for object hacks when C# 15 union types promise compile-time safety? Microsoft's .NET 11 preview delivers — but is it too late?

theAIcatchup Apr 09, 2026 3 min read

C# 15 union types eliminate if-else type checks with compile-time safety. 𝕏
Opt-in feature in .NET 11 Preview 2; GA November 2026. 𝕏
Boosts API parsing and validation; Microsoft's play to retain enterprise devs. 𝕏

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#.NET 11 #C# 15 #Type Safety #Union Types

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