乔伊·F·乔治-现代系统分析与设计（第6版）hoffer_msad6e_ch08a.pptVIP

? 2011 Pearson Education, Inc. Publishing as Prentice Hall Chapter 8 Appendix Object-Oriented Analysis and Design: Object Modeling – Class Diagrams Modern Systems Analysisand DesignSixth Edition Jeffrey A. Hoffer Joey F. GeorgeJoseph S. Valacich ? 2011 Pearson Education, Inc. Publishing as Prentice Hall * Chapter 8 Appendix Learning Objectives Concisely define each of the following key data modeling terms: object, state, behavior, object class, class diagram, operation, encapsulation, association role, abstract class, polymorphism, aggregation, and composition. Draw a class diagram to represent common business situations. Explain the unique capabilities of class diagrams compared with E-R diagrams for modeling data. ? 2011 Pearson Education, Inc. Publishing as Prentice Hall * Chapter 8 Appendix Representing Objects and Classes Object: an entity with a well-defined role in an application domain, and has state, behavior, and identity characteristics State: encompasses an object’s properties (attributes and relationships) and the values of those properties ? 2011 Pearson Education, Inc. Publishing as Prentice Hall * Chapter 8 Appendix Representing Objects and Classes (Cont.) Behavior: represents how an object acts and reacts Identity: uniqueness, no two objects are the same Object class (class): a logical grouping of objects that have the same (or similar) attributes, relationships, and behaviors (methods) ? 2011 Pearson Education, Inc. Publishing as Prentice Hall * Chapter 8 Appendix Representing Objects and Classes (Cont.) Class diagram: a diagram that shows the static structure of object classes, their internal structure, and the relationships in which they participate UML classes are analogous to E-R entities. ? 2011 Pearson Education, Inc. Publishing as Prentice Hall Representing Objects and Classes (Cont.) * Chapter 8 Appendix Figure 8-26 UML class diagram showing two classes ? 2011 Pearson Education, Inc. Publishing as Prentice Hall * Chapter 8 Appendi