Are there any rules for OOP?

Question

Recently I heard that there are 9 rules for OOP(Java). I know only four as Abstraction, Polymorphism, Inheritance and Encapsulation. Are there any more rules for OOP?

Answer 1

There are no "Rules" to OOP.

There are 4 language properties that make a language object-oriented or not (these are the things you listed in your question).

The rest of the material out there are guidelines. The best/most helpful guidelines I've read are GRASP

Many of the suggestions are not readily understandable by laymen (non-CS majors). I thought GRASP was pragmatic and approachable.

I think GRASP is nice because it suggests the most critical part of OO in its name - Assignment of Responsibility (to objects not programmers).

The two most critical GRASP concepts from which everything else derives are coupling and cohesion. These two concepts/principals drive all other patterns and approaches.

BTW - did I just interview you? You transcribed the question incorrectly...