Alan Kay the object-oriented parent summary of OOP features _oop

1. Everything is an object

2. The computation communicates with each other through the object, requests other objects to perform the action to implement. Communication between objects by sending and receiving messages. Messages are made up of requests for actions and parameters necessary to complete a task

3. Each object has its own memory, which may include other objects

4. Each object is an instance of a class, which is actually a group of similar objects, such as certificates or lists

5. Class is the repository of object-related customary behavior (repository). That is, all objects of the same class can perform the same action.

6. A class is organized into a tree structure with a single root node, called an inheritance hierarchy. Memory and behavior associated with class instances are automatically inherited by descendants in the tree structure