The document describes class diagrams and the relationships between classes. A class diagram shows classes and their attributes, operations, and relationships to other classes. The main types of relationships are: 1. Association - a relationship between classes that is represented by a solid line. 2. Dependency - a relationship where changes to one class may affect another class. 3. Generalization - a relationship between a superclass and subclass where the subclass shares properties of the superclass. 4. Realization - a relationship between a classifier that specifies a contract and another that guarantees to carry out the contract, such as between interfaces and classes.

1.  Presented by
◦ Ramesh V. Gurram
◦ (cm dept 3rd year )

2. A class diagram describes the set of Classes in a
system and the static relationships between
them.

3.  Describes a set of objects having similar:
◦ Attributes (status)
◦ Operations (behavior)
◦ Relationships with other classes
 Attributes and operations may
◦ have their visibility marked:
◦ "+" for public
◦ "#" for protected
◦ "−" for private
◦ "~" for package
UML Class Diagrams 3
Window
size: Size
visibility: boolean
display()
hide()
Class
Name
Attribute
s
Operatio
ns

4. Class
• class is abstract concept
• each object is instance of a class
• classes classify objects
• attribute has no values
Class
Customer
Custno
Name
Address
Order
Orderno
dateReceived
Price
Object analysis  than values to attributes

5. • Attribute has no values
• Association is relation between classes
Class Diagram
Customer
Cust_no
Name
Address
Order
Order_no
Date_Received
Price
Link is instance of association
1 *

6. Library Management System

7. Relationships
1) Association:-
• Association is a relationship between classes .
OR
•Association is a set of links.
It is represented by solid line.
Notation
Employee Company

8. 2) Dependancy
Dependancy is the relationship between two things in which
changes to one thing(independent thing) may affect on other
thing(Dependent thing).
Notation

9. 3)Genralisation
Genralisation is the relationship between a superclass
and subclass where subclass shares the properties of
superclass.
notation

10. 4)Realization
Realisation is relationship between classifier, where one
classifier specifies
A contract and another classifier guarantees to carryout.
It is relatiopnship between interface sand classes .
notation