C# 8 introduces nullable reference types to help prevent null reference exceptions. Developers can now explicitly mark reference types as nullable or non-nullable. The compiler will issue warnings for potential null reference issues like dereferencing a null value. This feature is available in Visual Studio 2019 and aims to reduce bugs by catching nullability issues at compile time rather than runtime. C# 8 also includes other new language features.

1. Non-nullable reference types in C#8
By John Staveley
28/02/2019
https://uk.linkedin.com/in/johnstaveley/
@johnstaveley

2. Nulls - The billion dollar mistake?
Tony Hoare (QCon 2009)
“[The null reference type] has led to innumerable errors,
vulnerabilities, and system crashes, which have probably
caused a billion dollars of pain and damage in the last forty
years.”

3. Nullable reference types in C#8
The old way of creating a nullable reference type:
The new way:
In C#8, these will cause compiler warnings:

4. Null ignoring/forgiving operator !
CS8602: Possible dereference of a null reference

5. Nullable reference types in C#8
“Explicitly setting you reference types correctly will lead to
fewer runtime errors and better design”
.csproj tags to set for entire project
Compiler directives to set on a class by class basis
Sidecar pattern for existing NuGet packages

6. What/When?
Visual Studio 2019 (Visual Studio Version 2016 Preview 1)
https://github.com/dotnet/roslyn/blob/master/docs/Language%20Feature
%20Status.md
Other things coming in C#8

7. What/When?
Visual Studio 2019 (Visual Studio Version 2016 Preview 1)
https://github.com/dotnet/roslyn/blob/master/docs/Language%20Feature
%20Status.md
Other things coming in C#8