C# - Get date difference of Nullable DateTime in int

Question

I have two DateTime variables of Nullable types.

DateTime? date1 = new DateTime();
DateTime? date2 = new DateTime();

I need to get the differe

Answer 1

I would write something like:

int? daysBetweenDate = date1.HasValue && date2.HasValue ? (int?)(date2.Value - date2.Value).TotalDays : null;

So daysBetweenDate is null if at least one of date1 and date2 is null.

Answer 2

If your goal is to return null when one (or both) of the dates is null, you can write like this (if you can use ? operator which is available in C# 6.0 compiler):

int? days = (int?) (date1 - date2)?.TotalDays;