 UML Intro  Objects  Object-Oriented Concepts  Classes  Attributes  Operations  Responsibilities & Constraints  Notes 1 SDES 6300 January 2011

The information contained in the following slides has been referenced from:  Textbook, Chapter 1, Pages 29 – 35  Textbook, Chapter 6, Pages , SDES 6300 January 2011

 Developed in the mid 1990’s  Broken into 2 major types of representations: Structure and Behavioral  Structure represents Objects within the System to be described (Class, Object, Package, etc)  Behavioral represent behavior of Objects (Activity, Sequence, Use Case) SDES 6300 January

 Represented as a rectangle in the UML  By convention, the name of the class starts with an initial uppercase letter  The package name can also appear in a class name – double colons separate the package name and the class name 4 WashingMachineHousehold::WashingMachine SDES 6300 January 2011

 An attribute is a property of a class  A class may have zero or more attributes 5 SDES 6300 January 2011

 An attribute can show its type as well as a default value 6 SDES 6300 January 2011

 An operation is something a class can do  You can show an operation’s parameter name & its type by including it in the parentheses after the operation name  You can also show the value an operation returns and its value’s type (known as a function) 7 SDES 6300 January 2011

 An ellipsis … indicates that the displayed attributes or operations aren’t the whole set. Omitting some or all of the attributes or operations is called eliding a class  You can use a keyword to organize a list of attributes or operations. A keyword is enclosed inside two pairs of small angle brackets called guillemets 8 SDES 6300 January 2011

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 Classes are the vocabulary and terminology of an area of knowledge  Be alert to the nouns that clients use to describe the entities in their business – the nouns will become classes in your model  The verbs that you hear constitute the operations in those classes  The attributes will emerge as nouns related to the class nouns 10 SDES 6300 January 2011

 First create a system by creating a set of classes (component based approach to software development)  Then expand the system by adding capabilities and adding new components  Then reuse the classes you created when you build a new system 11 SDES 6300 January 2011

 Class - type of thing  Class is the general category, object is a specific instance  Each object in a class should be identifiable in some way  An object has attributes & operations (or properties & behaviours) 12 SDES 6300 January 2011