Is it necessary to override == and != operators when overriding the Equals method? (.NET)

Question

Or it\'s advisable to do that? Why?

Answer 1

It is not necessary, but a smart thing to do.

If you are creating a framework and another developer other than you are going to use the object you should override the == and !=. That way when a developer may use it they at least have the right logic to compare the 2 objects rather than just are the same in memory.

I would ensure that your == & != do call your equals method.

Answer 2

See Guidelines for Implementing Equals and the Equality Operator (==)

For Value Types (structs) "Implement == any time you override the Equals method"

For Reference Types (classes), "Most reference types, even those that implement the Equals method, should not override ==." The exception is for immutable classes and those with value-like semantics.

Answer 3

In addition to all the answers already here, don't forget to ensure GetHashCode() is consistent as well.