Smalltalk and Object Orientation: an Introduction - Free

do:
[:item |
Transcript show: item printString.
Transcript cr.]
Once you have defined all the methods, you are ready to use your Organize r. Figure 12.7 illustrates
how the Organizer might be used. For example, I have used the Workspace to create a new Organizer
and put some entries in it. Try your Organizer out in a similar way. Try extending it by addin g
additional functionality. For example, provide a way of deleting an address or replacing it with a new
one.
Figure 12.7: Using the Organizer class in a Workspace
12.8 The Financial Manager project
At certain points throughout the remainder of this book you will be asked to develop a small project.
This project will provide the basic functionality of the Financial Manager application.
The aim of the Financial Manager application is to keep a record of deposits and withdrawals from a
current account. Associated with this, it should keep an up to date balance, as well as allow statements
to be printed.
You should be able to:
1. Add deposits to the account for a specified amount.
2. Make payments (withdrawals) from the account for specified accounts.
3. Get the current balance.
4. Get a statement of all payments and deposits made, in the order in which they happened. This
statement should be printed to the Transcript.
To do this you sho uld use a collection class to hold the statement in conjunction with a new class
subclassed off the class Object, which will hold the current balance and handle deposits and
withdrawals.
Assuming the class you define is called FinancialManager, then you should be able to run the
following Smalltalk:
| aFinancialManager |
aFinancialManager := FinancialManager new.
aFinancialManager deposit: 25.00.
aFinancialManager withdraw: 12.00.
aFinancialManager deposit: 10.00.
aFinancialManager deposit: 5.00.
aFinancialManager withdraw: 8.00.
Transcript show: ‘The current balance is ‘ ,
FinancialManager balance printString.
Transcript cr.
aFinancialManager statement.
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