Page 185 - DCAP308_OBJECT_ORIENTED_ANALYSIS_AND_DESIGN

Unit 14: Steps for Class Design

Notes
At this stage, we need to add more information to these attributes, such as visibility and
implementation type. Furthermore, additional attributes can be identified to enable
implementation of the class:
#firstName: String
#lastName: String
#pinNumber: String
#cardNumber: String
#account: Account (instance connection)
To design the association between the BankClient and the Account classes, we need to add
an account attribute of type Account, since the BankClient needs to know about his or her
account and this attribute can provide such information for the BankClient class. This is an
example of instance connection, where it represents the association between the BankClient
and the Account objects. All the attributes have been given protected visibility.
Refining Attributes for the Account Class
Here is the refined list of attributes for the Account class:
#number: String
#balance: float
#transaction: Transaction (This attribute is needed for implementing the association between
the Account and Transaction classes.)
#bankClient: BankClient (This attribute is needed for implementing the association
between the Account and BankClient classes.)

At this point we .must make the Account class very general, so that it can be reused by the
checking and savings accounts.
Refining Attribute for the Transaction Class

The attributes for the Transaction class are these:
#transID: String
#transDate: Date
#transTime: Time
#transType: String
#amount: float
#postBalance: float
Refining Attributes for the ATM Machine Class
The ATM Machine class could have the following attributes:
#address: String
#state: String
Refining Attributes for the CheckingAccount Class

Add the savings attribute to the class. The purpose of this attribute is to implement the
association between the CheckingAccount and SavingsAccount classes.

Contd...

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