C++程序设计-面向对象

1-1面向对象初探

变量也是Object

Data: the properties  or status; is the core

Operations: the functions对外能提供的服务，给灯通电或者不通电。

                           map

Problem space --------------Solution space

 

object  oriented(00)

是一种组织  设计 和实现的思想(Designs&Implementations)

 

2-2 面向对象基本概念

对象之间通过message进行信息交换

Object send messages

　　Messages are

　　　　Composed by the sender

　　　　Interpreted by the receiver

　　　　Implemented by the methods

　　Messages

　　　　May cause receiver to change state

　　　　May return the result

 

Object vs.Class

　　Object(cat)

     　　 Represent things,events ,or concepts

      　　Respond to message at run-time

　　Class(cat class)

　　　　Define properties of instances

      　　Act like types in C++

 

OOP Characteristics

　　1.Evertything is an objetct.

　　2.A program is a bunch of objects telling each other what to do by sending messages.

　　3.Each Object has its own memory make up of other objects.

　　4.Every object has a type.

　　5.All objects of a particular type can receive the same messages.

 

An object has an interface

　　The interface is the way it receives messages.

　　It is defined in the class the object belong to.

 

Functions of the interface

　　如果有借口，那么可以很方便的换其他东西，做出在程序中可以拆换的东西

　　耦合-内聚，耦合性大是我们希望做到的。

　　Communication：与外界进行沟通。

　　Protection；如果有借口，就可以保护内部的Implementations，外边的借口了还是不变的。

 

The Hidden Implementation(隐藏实现)

　　Inner part of an object, data members to present its state, and the actions it takes

　　when messages is rcvd is hidden.

Class creators Vs. Client programmers

　　-Keep client programmer's hand off portions they should not touch.

　　-Allow the class creators to change the interval working of the class without 　 worrying how it will affect the client programmers.

 

Encapsulation（封装）

　　bundle data and methods dealing with these data together in an object

　　Hide the details of the data and action.

　　Restrict only access to the publicized methods.