Understanding IEquatable

Question

When I implement objects that I want to compare using the IEquatable<T> interface:

1. Why do I have to override Equals(object) method if I already implemented Equals(T)?
2. Can I use == and != operators once I implement IEquatable<T>?

Answer 1

1. From MS Docs article on IEquatable<T>:

   If you implement IEquatable<T>, you should also override the base class implementations of Equals(Object) and GetHashCode() so that their behavior is consistent with that of the Equals(T) method. If you do override Equals(Object), your overridden implementation is also called in calls to the static Equals(Object, Object) method on your class. In addition, you should overload the op_Equality and op_Inequality operators. This ensures that all tests for equality return consistent results.

2. No, operators do not use the Equals method. They must be overloaded separately to do so.