Null-conditional operator and !=

Question

With the introduction of Null-Conditional Operators in C#, for the following evaluation,

if (instance != null && instance.Val != 0)

Answer 1

With Null-Conditional operator returned value can always be null

if ((instance?.Val ?? 0) != 0)

If instance was null, then instance?.Val will also be null (probably int? in your case). So you should always check for nulls before comparing with anything:

if ((instance?.Val ?? 0) != 0)

This means: If instance?.Val is null (because instance is null) then return 0. Otherwise return instance.Val. Next compare this value with 0 (is not equal to).