Creating nullable class

Question

How do I create a nullable (?) class in C#? Like:

public class Hello1 {
  public int Property1 { get; set; }
}

public class Hello2 {
 Public Hello1? Property2 { get; set; } //Hello1 should work when it has "?"
}

I want to make Hello1 class to be able to take the form Hello1? if needed.

Answer 1

You don't need to create a nullable type for reference types. They're already nullable. You only need to do this for Value types like int, bool, decimal, etc...

Answer 2

You don't need to; reference types can already be null. As for structures, simply appending a ? will work. So just remove the ?, and check for null using == null, as usual.

Answer 3

Just remove the questionmark. All classes are nullable by default. Only value-type objects (like struct) need to be explicitly made nullable.

Answer 4

All classes are nullable. nullable is for Value types that can't be null