(Account Inheritance Hierarchy) Create an inheritance hierarchy that a bank
might use to represent customers' bank accounts. All customers at this bank
can deposit (i.e., credit) money into their accounts and withdraw (i.e.,
debit) money from their accounts. More specific types of accounts also exist.
Savings accounts, for instance, earn interest on the money they hold. Checking
accounts, on the other hand, charge a fee per transaction (i.e.. credit or
debit).
Create an inheritance hierarchy containing base class account and derived
classes savingsAccount and checkingAccount that inherit from class Account.
Base class Account should include one data member of type double to represent
the account balance. The class should provide a constructor that receives an
initial balance and uses it to initialize the data member. The constructor
should validate the initial balance to ensure that it is greater than or equal
to \(\theta . \theta .\) If not, the balance should be set to \(\theta . \theta\)
and the constructor should display an error message, indicating that the
initial balance was invalid. The class should provide three member functions.
Member function credit should add an amount to the current balance. Member
function debit should withdraw money from the account and ensure that the
debit amount does not exceed the account's balance. If it does, the balance
should be left unchanged and the function should print the message "Debit
amount exceeded account balance." Member function getBalance should return the
current balance.
Derived class savingsAccount should inherit the functionality of an Account,
but also include a data member of type double indicating the interest rate
(percentage) assigned to the Account. SavingsAccount's constructor should
receive the initial balance, as well as an initial value for the
SavingsAccount's interest rate. SavingsAccount should provide a public member
function calculateInterest that returns a double indicating the amount of
interest earned by an account. Member function calculateInterest should
determine this amount by multiplying the interest rate by the account balance.
[Note:
SavingsAccount should inherit member functions credit and debit as is without
redefining them.]
Derived class checkingAccount should inherit from base class Account and
include an additional data member of type double that represents the fee
charged per transaction. CheckingAccount's constructor should receive the
initial balance, as well as a parameter indicating a fee amount. Class
CheckingAccount should redefine member functions credit and debit so that they
subtract the fee from the account balance whenever either transaction is
performed successfully. CheckingAccount's versions of these functions should
invoke the base-class account version to perform the updates to an account
balance. CheckingAccount's debit function should charge a fee only if money is
actually withdrawn (i.e., the debit amount does not exceed the account
balance). [Hint: Define Account's debit function so that it returns a bool
indicating whether money was withdrawn. Then use the return value to determine
whether a fee should be charged.]
After defining the classes in this hierarchy, write a program that creates
objects of each class and tests their member functions. Add interest to the
SavingsAccount object by first invoking its calculateInterest function, then
passing the returned interest amount to the object's credit function.
