Crazy java--Second Chapter understanding object-oriented

Three main features of object-oriented: inheritance, encapsulation and polymorphism

The object-oriented approach is actually made up of OOA (object-oriented analysis), OOD (object-oriented design), and OOP (face object programming) three parts, where OOA and OOD structures need to be described and documented in a descriptive way, At present, the industry unifies UML (Unified Modeling Language) to describe and record the results of OOA and Ood.

Object-oriented and object-based differences: objects are also used, but there is no way to generate new object types from existing object templates-that is, objects are not inherited and polymorphic. JavaScript is Object-based.

In the Java language, everything is an object except for 8 basic data types.

General---Special: inheritance to implement

Overall--part: combination, a class that holds a reference to another object.

Crazy java--Second Chapter understanding object-oriented