Obj is null vs object.ReferenceEquals(Obj, null)

Question

What is the difference between

if (Obj is null) Console.WriteLine("Value is null");

if (object.ReferenceEquals(Obj, null)) Console.WriteLine("Value is null");

I am trying to override the == operator and as such cannot use Obj == null.

Since `object.ReferenceEquals()` internally is `==` check ([ReferenceEquals](https://referencesource.microsoft.com/#mscorlib/system/object.cs,4d607d6d56a93c7e,references)), then: Possible duplicate of [What is the difference between "x is null" and "x == null"?](https://stackoverflow.com/questions/40676426/what-is-the-difference-between-x-is-null-and-x-null) — SᴇM, May 21 '19 at 10:38

score 0 · Answer 1 · edited May 21 '19 at 17:00

0

ReferenceEquals(obj, null) and (obj is null) do exactly the same thing, but the latter is only available as part of C# 7.0 syntax and later.

edited May 21 '19 at 17:00

Matthew Layton

answered May 21 '19 at 10:37

Steve Todd

I don't know who is down-voting this but IIRC, this is exactly right! – Matthew Layton May 21 '19 at 10:39
https://github.com/dotnet/docs/issues/6856 – Matthew Layton May 21 '19 at 10:42

1 Answers1