How to Compare Two Objects in the Real World

Each object is seen as being a uniquely identifiable entity regardless of its attributes. If you have two objects, the default is that they are equal if their references are equal. There's no language level construct for determining how to compare two objects. OOP suffers directly from the problems associated with state described above direct. It's just got mutable state, we've already talked about that it's got this exponential number of possible states.