Overriding == operator. How to compare to null? [duplicate]

Answer 1

Cast the Person to an Object and then perform the comparison:

object o1 = (object)person1;
object o2 = (object)person2;
if(o1==o2) //compare instances.
   return true;
if (o1 == null || o2 == null)  //compare to null.
   return false;
//continue with Person logic.