Object Oriented Programming

• Class Diagrams:
  • Lets draw a sample class diagram of Company, Department and Employee (Without representing relationships b/w them)

Association, Aggregation and Composition

• Association: This represents the unidirectional or bidirectional relationship b/w two classes.

• Associations are of two types

  • Aggregation: An object can exist even if the object of control class is dead (Company, Building)
  • Composition: An object also will be dead if the object of control class is dead (Company, Department)

• Lets create a Class Diagram for a Library

  • Librarian
  • Book
  • User

• Generally relationships b/w classes can be classified into two major categories

  • is-a
  • has-a: Represents aggregation/composition

• Lets create a Class Diagram for Movie Booking

  • Movie
  • Theatre
  • Screen
  • User
  • Ticket

• Exercise: Create a Class Diagram For Bank with ATM for ATM Operations

  • Bank
  • Customer
  • Account
  • Teller