Class diagram java
- 1. Prepared by-Ravin Laheri (160120107054) Guided by –Prof . Chintan Shah Gandhinagar Institute of Technology Subject Code(2150704) Explain class diagram.
- 2. What is a Class? A general template that we use to create specific instances or objects in the application domain Represents a kind of person, place, or thing about which the system will need to capture and store information Abstractions that specify the attributes and behaviors of a set of objects Explain class diagram.2
- 3. What is an Object? Entities that encapsulate state and behavior Each object has an identity It can be referred individually It is distinguishable from other objects Explain class diagram.3
- 4. Types of Classes Ones found during analysis: people, places, events, and things about which the system will capture information ones found in application domain Ones found during design specific objects like windows and forms that are used to build the system Explain class diagram.4
- 5. Two Kinds of Classes during Analysis Concrete Class from application domain Example: Customer class and Employee class Abstract Useful abstractions Example: Person class Explain class diagram.5
- 6. Attributes in a Class Properties of the class about which we want to capture information Represents a piece of information that is relevant to the description of the class within the application domain Explain class diagram.6
- 7. Attributes in a Class Only add attributes that are primitive or atomic types Derived attribute attributes that are calculated or derived from other attributes denoted by placing slash (/) before name Explain class diagram.7
- 8. Operations in a Class Represents the actions or functions that a class can perform Describes the actions to which the instances of the class will be capable of responding Can be classified as a constructor, query, or update operation Explain class diagram.8
- 9. UML Representation of Class Class Name Attributes of Class Operations/methods of Class Explain class diagram.9
- 10. Example of a Class Diagram Video Rental System methods class name Video +rentMovie() Customer -CID: int -name: String +authenticateCustomer () relationship rents 1..*1..* multiplicityvisibility attributes -cassetteID : int -cassetteVolumeNo: int Explain class diagram.10
- 11. THANK YOU Explain class diagram.11
Editor's Notes
- #6: Concrete Used to create objects Abstract Person class is really a generalization from Customer class and Employee class Attributes and methods common to both Customer class and Employee class Examples of common attributes: name, address, birthdate, phone number, email address Generally do not create objects from Person class but rather create and use employee and customer objects Later in the design and implementation phases, we will also identify other classes such as user interface classes, data structure classes, document classes, file structure classes, operating environment classes, and various types of multimedia classes.
- #7: Attributes in a Class Contains information that the analyst or user feels that the system should store Represents properties that describe the state of the object Only attributes important to the task should be included in the class For example, for employee, employee name is a good attribute; employee hair color is not (not relevant in the business application) Primitive or atomic types Such as integer, string, double, date, time, boolean, … Generally complex or compound attributes are really placeholders for relationships between classes
- #8: Attributes in a class diagram Typed in middle compartment Derived attributes Examples: age (subtracting birthdate from current date), GPA (calculated from grades and credit hours)
- #9: Operations in a Class Represents the actions or functions that a class can perform In later phases, the operations are converted to methods (functions in C++) Only problem domain-specific operations that are relevant to the problem should be considered Classes normally are required to provide the means to create instances, delete instances, access individual attribute values, set individual attribute values, and other basic types of operations At this point in development, don’t clutter up the definition of the class with these basic types of operations Focus only on relevant problem domain-specific operations 1)Constructor operation Creates a new instance of a class Since creation is normally available to all classes, typically will not see constructor methods at this point in the development of the class diagram 2)Query operation Makes information about the state of an object available to other objects but will not alter the object in any way 3)Update operation Changes the value of some or all of the object’s attributes which may result in a change in the object’s state
- #10: Class representation Compartmentalized rectangles Top compartment: name of class Middle compartment: structure of the class (attributes) Bottom compartment: behavior of the class (operations)
- #11: -cassetteID: int -cassetteVolumeNo: int