由为对象定义的一系列操作决定
机票代理
核对出发时间
(返回 9:27)
班机 747
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对象的行为
Behavior determines how an object acts and reacts.
The visible behavior of an object is modeled by a set of messages it can respond to (operations that the object can perform).
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Object
Informally, an object represents an entity, either physical, conceptual, or software
Physical entity
Conceptual entity
化学过程
Software entity
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Class
A class is a description of a set of objects that share the same attributes, operations, relationships, and semantics.
An object is an instance of a class.
UML建模语言及工具
第2 章 对象技术与可视化建模基础
An Overview ofg
Review： An Approach to the Object-Oriented
上升到面向对象
面向对象技术概述
定义、利益、研究内容
Professor Clark’s behavior Submit Final Grades Accept Course Offering Take Sabbatical Set Max Load
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TakeSabbatical()
Professor Clark
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Sample-An Object
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Representing Objects in the UML
An object is represented as a rectangle with an underlined name.
J Clark : Professor
Named Object
: Professor
Anonymous Object
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可能的状态： 停泊 运营 着陆 终止
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对象的状态
State is a condition or situation during the life of an object, which satisfies some condition, performs some activity, or waits for some event.
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班机 747 on 11/12
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对象的标识
Professor “J Clark” teaches Biology
Professor “J Clark” teaches Biology
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对象的状态
一个对象的状态是它反映于现实世界的 一系列属性：
参数的数值 (也就是,与对象有关系的数据) 它与其它对象的关系
The state of an object normally changes over time.
Name: J Clark Employee ID: 567138 Date Hired: July 25, 1991 Status: Tenured Discipline: Finance Maximum Course Load: 3 classes
面向对象技术发展
历史（里程碑）、现状、未来
面向对象与结构化
扬弃而非否定
上升到面向对象
利用面向对象的观点认识客观问题
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学习线路图
OO UML
OOA
:
:
OOD DP
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… Case-Study …
学习线路图
……………………
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Agenda 1
Object and Class Four Principles of OO Generalization and Polymorphism Principles of Visual Modeling The UML Process and visual modeling
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Name: J Clark Employee ID: 567138 HireDate: 07/25/1991 Status: Tenured Discipline: Finance MaxLoad: 3
Professor Clark
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对象的行为
定义当其它对象发出请求时，该对象如 何反应
A class is an abstraction in that it
Emphasizes relevant characteristics. Suppresses other characteristics.
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Sample-A Class
Properties
Class Employee
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链表
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Object-Formal Definition
An object is an entity with a well-defined boundary and identity that encapsulates state and behavior.
Attributes
State is represented by attributes and relationships.
Behavior is represented by operations, methods, and state machines.
Object
Operations
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对象的标识
每一个对象都有一个唯一的标识, 即使其 状态有可能与其它对象一样
班机 747 on 11/10
班机 747 on 11/11