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.)