How can an application program (such as main()
)
change the balance of a CheckingAccount
object?
By using the methods such as processDeposit()
and processCheck()
that have been
written for that purpose.
A class with private data controls access to that data
by using
access methods.
An access method is a method which uses the private data of its class
and is visible to other classes .
Some access methods alter data; others return a value
but don't alter data.
Here is a main()
that uses the access methods of the CheckingAccount
object
bobsAccount
.
class CheckingAccount { private String accountNumber; private String accountHolder; private int balance; . . . . } class CheckingAccountTester { public static void main( String[] args ) { CheckingAccount bobsAccount = new CheckingAccount( "999", "Bob", 100 ); System.out.println( bobsAccount.currentBalance() ); bobsAccount.processDeposit( 200 ); System.out.println( bobsAccount.currentBalance() ); } }
(If you want to run this program, copy and paste from the previous page and this page into Notepad.)