Coding Shorts: Nullable Reference Types: Or, Why Do I Need to Use the ? So Much!
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- เผยแพร่เมื่อ 26 ก.ค. 2024
- As the C# language matures, Microsoft has now made Nullable Reference Types the default in new projects. It might be confusing why this was done. Let's find out:
00:00 - Introduction
00:32 - Creating a Project
01:02 - Before Nullable Reference Types
03:45 - Using Nullable Reference Types
09:16 - Nullable Reference Types in Generics
12:01 - Wrapping Up
Source code: github.com/shawnwildermuth/co...
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Shawn, you did an outstanding job of clarifying this new feature. I was struggling to understand why this was done. It now make sense to me. Thanks 😊
Happy to help!
you have unusual way to simplify anything in a minute, great explanation as usual, thank you so much
Brilliantly explained in such a short way! Thanks a lot for your educational lessons 😊
This information was exactly what I was looking for. Greate stuff Shawn. Thanks for sharing your knowledge.
Glad it helped
Extemely well done video, full and concise; have watched many video tutorials over the years both on YT, Pluralsight, etc; format is excellent.
Thanks for the video! 👍 Sometime for new projects, I add Nullable to the csproj, so the code won't compile unless I fix nullability issues. This makes me understand the concept better.
Amazing video! The only video that cleared up for me why there's such a thing as nullable ref types. In short, it was to eliminate ambiguity by forcing an explicit declaration of intent. I also enjoyed the latter half where you went into the operators and the generic example.
Glad it helped!
Well, that was a clear explanation. Thanks Shawn.
Glad it was helpful!
Amazing video, thanks for putting it together!
Thanks for the clear explanation on this. One thing that might be missing is that you can also get ris of the "may be null" warning by performing a null check somewhere before in the code.
To me the addition of nullabel reference types possibly had the biggest impact of all newer features and i would never deactivate it on a new project now.
Migrating old code can be a pain though ...
most important change in the last 5 years. Paying attention to this as the tools are trying to make you do, massively improves your design.
How? Can you elaborate on this?
Your content is amazing.. well done! don't stop!!
Ok!
Great video, really helped me thank you. Although the word null kept going funny in my head. Haha
Nice one. Thank you
Always welcome
Thanks for great video!
My pleasure!
Nice explaination.
Glad you liked it
good explanation
Thanks and welcome
short and clear
Glad you liked it.
Thanks, very good stuff. What would you say are the benefits, for developers and the applications we build. I know you did mention it in the end, but I somehow got the impression of "just do it" rather than "do it so that your code will ..."
I think the benefit is more transparency to what you expected. By specifying nullability, you're telling the developer after you what you expect. Whereas before Nullable Reference Types, I didn't have a way of saying "This will never be null".
@@swildermuth I also like that the code, when in runtime, will not (hopefully) get "null ref"-issues. Or am I misunderstanding ?
@@jedjohan That's true (harder to get null ref issues, but not impossible)
Cool channel. Thanks. I have been uneducated about how this feature works. Now I ain't. :D
I switched to using result / option / elevated types from the functional world in my c# and never looked back. Nullable and handling of them was a terrible idea for c#. I get its backward compatibility but time to evolve.
Immutability and nullability are not the same issue. But I'm glad it is working for you.
It's funny how c# is now doing the same thing java did with generics decades ago. Provide an optional "upgrade" to the new system and all old stuff is now a warning.
And seeing that this "slow migration system" never completed in java we can assume that c# will have projects with nullabity and without for pretty much forever.
How to create project by n new instead of dotnet new? when I use it I get error: n : The term 'n' is not recognized as the name of a cmdlet
Sorry, it is "dotnet new" - I just have a batch file that redirects to dotnet so I only have to type "n"
At 3:00 - "int? x = default" - the value is not 0 but null! (I was testing code as you were displaying it)
Which brings me to my next question, why isn't it clear by the compiler what "default" value is!
Null isn't the default for anything. Default for value types are typically 0 for numeric types.
when I scaffold the database using EF Core I get a lot of warnings about nullable
The scaffolding hasn't caught up with it. I don't have a good solution (adding the "#nullable disable" on every file isn't scalable really).
What version of .NET Core are you using? You might need to get the latest version of EF Tools. It is handling the null-ness in my recent projects.
@@swildermuth I am using .NET 7 and the dotnet-ef is 7.0.2 but in .NET 6 I also had the same warnings, I tried NullableReferenceTypes but not working in my case I can send more info if needed
9:25
In fact the code:
var len = user.Name?.Length;
len is of type int?
var len = user.Name!.Length;
len is of type int
in short. "nullable reference types" enabled makes reference types into "value types". the name "nullable reference types" is quite bad, defeats it's own purpose. They should have called it "non-nullable reference types"
C# is a Frankenstein language for a long time. Now this nullable stupity is made so that the code is easily read and used by the AI... I hate it
Not sure how AI plays into it. But you're able to not use nullable reference types. There seems to be a separation into two dialects of the language over the years. C# 13 is the maturation of including more functional ideas, but it's all opt-in. You don't have to use it if it's not serving your needs.
This feature adds unnecessary complexity to the c# language.
Great explanation
Glad you liked it.