c# - Why does Nullable<T> HasValue property not throw NullReferenceException on Nulls?

Question

Consider the following code:

DateTime? ndate = null;
Console.WriteLine(ndate.HasValue);

I would have expected a NullReferenceException, but HasValue will indeed return false. However, since ndate is null, how does the property invocation succeed, since there is no object to invoke the property HasValue on?

Answer 1

Technically, "ndate" is not null - it is a value type, with it's value specified as being null.

When you write DateTime?, this is just shorthand for Nullable<DateTime>, which is a struct. There is no way for this to technically be null, since it's not a reference type.