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

Not sure about any rules. All these mentioned things are more like OO paradigms to me. There are few advices we follow like,

• Separation of Concern
• Single Responsibility per Class
• Prefer Composition over Inheritance
• Programming to Interface
• Plus all mentioned by Billybob, already