How to set null to a GUID property

Question

I have an object of type Employee which has a Guid property. I know if I want to set to null I must to define my type property as nullable Nullable

Answer 1

I think this is the correct way:

Guid filed = Guid.Empty;

Answer 2

Guid? myGuidVar = (Guid?)null;

It could be. Unnecessary casting not required.

Guid? myGuidVar = null;