Working with records

Before we dive into the new records language feature, let us see some other related new features of C# 9 and later.

Init-only properties

You have used object initialization syntax to instantiate objects and set initial properties throughout this chapter. Those properties can also be changed after instantiation.

Sometimes, you want to treat properties like readonly fields so they can be set during instantiation but not after. The new init keyword enables this. It can be used in place of the set keyword:

1. In the PacktLibraryNetStandard2 project/folder, add a new file named Records.cs.
2. In Records.cs, define a person class with two immutable properties, as shown in the following code:

   namespace Packt.Shared;
   public class ImmutablePerson
   {
     public string? FirstName { get; init; }
     public string? LastName { get; init; }
   }
   

3. In Program.cs, add statements to instantiate a new immutable person and then try to change one...