Where would you use the new C# 9 Record Type

Hi!
Records will be really useful in cases where we are looking for immutable data. Examples:

• DTOs
• Events when working in event sourcing
• Commands
• ...

I recommend you to read this blog post (pre-records) by Jimmy Bogard when he explains the challenges of immutable classes in .net. Know, with records, it's embedded in the language.

jimmybogard.com/immutability-in-dtos/

Agree with that. Kind of like what I do with kotlin and java. Data stuff is data class (record in C# and java). Services and others are class so it can mutate itself. In Java I just make stuff final if it's not used by some naggy framework until records are stable

Hi Ninja,
Thanks for the comment. What you said makes a lot of sense to me: if you need to move data from one to another use a record.
IMHO records could also become a bit of a pain, if not used correctly. Think about this:

public class Foo
{
    public string S1 {get;set;}
    public string S2 {get;set;}
}

record Bar(int i1, Foo f);

I think records could be also really helpful to serialize and deserialize stuff (because it reduces the lines of code by a lot).

I totally agree. IMHO, immutability should be the default and mutable properties should be used with caution. This also means I prefer having readonly collections whenever possible.