I always used
Nullable<>.HasValue because I liked the semantics. However, recently I was working on someone else's existing codebase where they used
Nullable<> != null exclusively instead.
Is there a reason to use one over the other, or is it purely preference?
int? a; if (a.HasValue) // ...
int? b; if (b != null) // ...
The compiler replaces null comparisons with a call to
HasValue, so there is no real difference. Just do whichever is more readable/makes more sense to you and your colleagues.
(a != null) so that the syntax matches reference types.