Lambda Expression: == vs. .Equals()

Question

This is a purely academic question, but what\'s the difference between using == and .Equals within a lambda expression and which one is preferred?

Code exam

Answer 1

It depends on what defined for the object. If there's no operator== defined for the class, it will use the one from the Object class, which checks Object.ReferenceEquals before eventually calling Equals().

This shows an important distinction: if you say A.Equals(B) then A must be nun-null. if you say A == B, A may be null.