Basic Principles of Object Orientation（面向对象的基本概念）

Abstraction（抽象）

• emphasizes relevant characteristics
• suppresses other characteristics

Encapsulation（封装）

• Encapsulation means to design, produce, and describe software so that it can be easily used without knowing the details of how it works.
• Also known as information hiding

Inheritance（继承）

• Inheritance —a way of organizing classes
• Classes with properties in common can be grouped so that their common properties are only defined once.
• Is is “a kind of” relationship

Polymorphism（多态）

• The ability to hide many different implementation behind a single interface.