School of Computer Science and Engineering Class Diagrams Bong-Soo Sohn Assistant Professor School of Computer Science and Engineering Chung-Ang University

CLASS in UML Class Name Attribute1 Attribute2 … Operation1 Operation2 responsibility

CLASS in UML Class name WashingMachine First letter is upper-case No empty space in a class name. with package name? package_name::class_name Ex) HouseholdAppliances::WashingMashine WashingMachine

myWasher:WashingMachine CLASS in UML Attribute Attribute Names Additional information (attribute vale) can be specified. Ex) capacity:Integer = 8 WashingMachine brandName modeName serialNumber capacity Instance of WashingMachine myWasher:WashingMachine brandName = “TROMM” modeName = “WD-R121XH” serialNumber = “LG57774” capacity = 12

CLASS in UML Operation WashingMachine brandName class methods modeName addClothes() removeClothes() addDetergent() turnOn() brandName modeName serialNumber capacity WashingMachine class methods first letter is lower-case Additional information (e.g. signature) can be specified. Ex) addClothes( C:String )

Additional information (signature) in operations WashingMachine brandName modelName serialNumber capacity addClothes( C:String ) removeClothes( C:String ) addDetergent( D:Integer) turnOn( ):Boolean - Parameter name and type - Return type

Stereotype WashingMachine WashingMachine WashingMachine brandName . . . addClothes() WashingMachine <<id info>> brandName modelName serialNumber <<machine info>> capacity <<clothes-related>> addClothes() removeClothes() addDetergent() <<machine-related>> turnOn() If the lists of class attributes and operations are long, stereotype can be used to separate the list for better understanding. stereotype one or extensibility machanisms in UML allow designers to extend the vocabulary of UML in order to create new model elements Notation :<<stereotype_name>>

Responsibility and Constraints Use when inserting constraints a class has to follow. Notation : text in ‘{ }’ WashingMachine <<id info>> brandName modelName serialNumber <<machine info>> capacity <<clothes-related>> addClothes() removeClothes() addDetergent() <<machine-related>> turnOn() Responsibility : Take dirty clothes as input and produce clean clothes as output {capacity =5 or 8 or 10 Kg} Explain what class has to do

Note WashingMachine brandName modelName serialNumber capacity <<id info>> brandName modelName serialNumber <<machine info>> capacity <<clothes-related>> addClothes() removeClothes() addDetergent() <<machine-related>> turnOn() Responsibility : Take dirty clothes as input and produce clean clothes as output Refer to Government Standard EV5-2241 on generating serial numbers {capacity =5 or 8 or 10 Kg} Note Use when inserting additional information.

Class Modeling Class name attribute1 attribute2 … operation1 Nouns during conversation with clients Class name attribute1 attribute2 … operation1 operation2 responsibility Nouns during conversation with clients , which are related to class name. Verbs during conversation with clients의뢰

Example : modeling basketball game

Example : modeling basketball game

Basketball Game Conversation with coach noun ball, basket, team, players, guards, forwards, cener, shot, shot clock, three-point line, free throw, foul, free-throw line, court, game clock verb Shoot, advance, dribble, pass, foul, rebound Initial Class Diagram

Initial class diagram Ball diameter volume dribble() shoot() pass() advance() Player name height weight dribbleBall() passBall() shootBall() rebound() foulOpponent() Forward does most of the intermediate range shooting and rebounding Guard does most of the dribbling and passing Team Basket ShotClock {pro = 24 sec college = 35sec Int’l = 30 sec} center stays near basket, shoots from close range Foul Shot Court GameClock {pro = 4 12-minute quarters college and Int’l=2 20-minute halves} ThreePointLine FreeThrow Duration {pro = 48minutes college and Int’l = 40 minutes FreeThrowLine

Association When classes are connected together conceptually, that connection is called association

Association

Constraints on Association

Association Classes Association can have attributes and operations, just like a class.

Link An association may have instances, just as an object is an instance of a class

Multiplicity The number of objects from one class that relate with a single object in an associated class. One – to – one One – to – many(*) One – to – one or more(*) 1..* One – to – zero or one One – to – a bounded interval ex. one – to – 5 through(..) 10 One – to exactly n ex. One – to – 10 One – to – a set of choices ex. One – to – 5 or(,) 10

Multiplicity Possible multiplicities and how to represent them in UML

Reflexive Association Association with itself

Inheritance and Generalization Is a kind of inheritance, Generalization subclass , superclass root class, leaf class

abstract class Class that does not have an instance italic font

Dependencies one class may use another. The most common usage of dependency is to show that the signature of one class’s operation uses another class

More about class diagrams 집합연관(Aggregation) 복합연관(Composition) 문맥(Contexts) 인터페이스(Interface) 실체화(Realization) 가시성(Visibility)

Aggregations A class consists of a number of component classes

Constraints on Aggregations Constraint to show that one component or another is part of whole

Composite A strong type of aggregation Each component in a composite can belong to just one whole

composite structure diagram Show class’s internal structure Show components of a class

Interface and Realization One entity (interface) defines a set of functionalities as a contract, and the other (class) realizes the contract by implementing the functionality defined in the contract.

Visibility + : public # : protected - : private