Question

Whats the difference between these two comparison statments?

var result = EqualityComparer<T>.Default.Equals(@this, null);
var result = @this == null;

Obviously the aim is to test whether the object ‘@this’ isnull.

Answer 1

operator == calls ReferenceEquals on comparing objects, so compare that objects are pointing to the same memory location.

Equals, instead, is a just virtual method, so can behave differently for different types, as it can be overriden.

For example, for CLR string Equals compares content of a string and not a reference, even if string is a reference type.