class Diagram.ppt
- 1. Class Diagram & Object Diagram ATA.USAMA AMP/IT/2015/F/0018
- 2. What is a Class Diagram? A Class Diagram is a diagram describing the structure of a system. It consists the : Classes. Attributes. Operations. Relationships among the classes.
- 3. Classes A class is a description of a set of objects that share the same attributes , operations, relationships, and semantics. Graphically, a class is rendered as a rectangle, usually including its name , attributes, and operations in separate , designated compartments. ClassName attributes operations
- 4. Class Names The name of the class is the only required tag in the graphical representation of a class. It always appears in the top-most compartment. ClassName attributes operations
- 5. Class Attributes should include all fields of the object. Attributes are usually listed in the form: attributeName : Type A derived attribute is one that can be computed from other attributes, but doesn’t actually exist. Example; a Person’s age can be computed from his birth date. / age : Date Person name : String address : Address birthdate : Date / age : Date ssn : Id
- 6. Class Attributes (Cont..) Attributes can be: + public. # protected. - private. / derived. Person + name : String # address : Address # birthdate : Date / age : Date - ssn : Id
- 7. Class Operations Operations describe the class behavior and appear in the third compartment. Person name : String address : Address birthdate : Date ssn : Id eat sleep work play
- 8. Relationships There are three types of relationships you can set up between classes. Dependencies Generalizations Associations
- 9. Dependency Relationships A dependency indicates a semantic relationship between two or more elements. Symbolized by dotted line.
- 10. Generalization Relationships A generalization connects a subclass to its superclass. Generalization provides the capability to create supper classes that encapsulate structure and behavior common to several classes. specialization provides the ability to create subclasses that represent refinement to the supper-class.t.
- 11. Example :
- 12. Association Relationships If two classes in a model need to communicate with each other, there must be link between them. Here , an association is instructs Instructor Student instructs
- 13. Association Relationships(Cont..) We can indicate the multiplicity of an association by adding multiplicity adornments to the line denoting the association. The example indicates that a Student has one or more Instructors: Student Instructor 1..*
- 14. Thank You Kingsoft Office published by www.Kingsoftstore.com @Kingsoft_Office kingsoftstore