Test if object implements interface

Question

What is the simplest way of testing if an object implements a given interface in C#? (Answer to this question in Java)

Answer 1

If you want to use the typecasted object after the check:
Since C# 7.0:

if (obj is IMyInterface myObj)

This is the same as

IMyInterface myObj = obj as IMyInterface;
if (myObj != null)

See .NET Docs: Pattern matching with is # Type pattern