(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.

Create base class Account and derived classes SavingsAccount and CheckingAccount that inherit from class Account. Base class Account should include one private instance variable of type decimal to represent the account balance. The class should provide a constructor that receives an initial balance and uses it to initialize the instance variable with a public property. The property should validate the initial balance to ensure that it is greater than or equal to 0.0. If not, the balance should be set to 0.0, and the set accessor should display an error message, indicating that the initial balance was invalid. The class should provide two public methods. Method Credit should add an amount to the current balance. Method 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 method should print the message "Debit amount exceeded account balance." The class should also provide a get accessor in property Balance that returns the current balance.

Derived class SavingsAccount should inherit the functionality of an Account, but also include a decimal instance variable 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 interest rate. SavingsAccount should provide public method CalculateInterest that returns a decimal indicating the amount of interest earned by an account. Method CalculateInterest should determine this amount by multiplying the interest rate by the account balance. [Note: SavingsAccount should inherit methods Credit and Debit without redefining them.]

Derived class CheckingAccount should inherit from base class Account and include a decimal instance variable 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 methods Credit and Debit so that they subtract the fee from the account balance whenever either transaction is performed successfully. CheckingAccount's versions of these methods should invoke the base-class Account version to perform the updates to an account balance. CheckingAccount's Debit method 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 method 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 an application that creates objects of each class and tests their methods. Add interest to the SavingsAccount object by first invoking its CalculateInterest method, then passing the returned interest amount to the object's Credit method.

Try:

using System;

public class Account

{

decimal balance;

public decimal Balance

{

get { return balance; }

set

{

if (value >= 0.0M)

{

balance = value;

}

else

{

balance = 0.0M;

Console.WriteLine("Initial balance was invalid. Zero used");

}

public Account(decimal balance)

{

Balance = balance;

}

public virtual void Credit(decimal amount)

{

balance += amount;

}

public virtual bool Debit(decimal amount)

{

if (amount <= balance)

{

balance -= amount;

return true;

}

else

{

Console.WriteLine("Debit amount exceeded account balance");

return false;

}

public class SavingsAccount : Account

{

decimal interestRate;

public SavingsAccount(decimal balance, decimal interestRate) : base(balance)

{

this.interestRate = interestRate;

}

public decimal CalculateInterest()

{

return Balance * interestRate / 100m;

}

public class CheckingAccount : Account

{

decimal fee;

public CheckingAccount(decimal balance, decimal fee) : base(balance)

{

this.fee = fee;

}

public override void Credit(decimal amount)

{

base.Credit(amount);

Balance -= fee;

}

public override bool Debit(decimal amount)

{

if(base.Debit(amount))

{

Balance -= fee;

return true;

}

else

{

return false;

}

class Program

{

static void Main()

{

Account acc1 = new Account(100);

Console.WriteLine("The intial balance of account 1 is {0:C}", acc1.Balance);

acc1.Credit(100);

acc1.Debit(50);

Console.WriteLine("The final balance of account 1 is {0:C}", acc1.Balance);

Console.WriteLine();

Account acc2 = new Account(-100);

Console.WriteLine("The intial balance of account 2 is {0:C}", acc2.Balance);

acc2.Credit(30);

acc2.Debit(40);

Console.WriteLine("The final balance of account 2 is {0:C}", acc2.Balance);

Console.WriteLine();

SavingsAccount acc3 = new SavingsAccount(100, 5);

Console.WriteLine("The intial balance of account 3 is {0:C}", acc3.Balance);

acc3.Credit(200);

acc3.Debit(40);

Console.WriteLine("The current balance of account 3 is {0:C}", acc3.Balance);

decimal interest = acc3.CalculateInterest();

acc3.Credit(interest);

Console.WriteLine("The final balance of account 3 is {0:C}", acc3.Balance);

Console.WriteLine();

CheckingAccount acc4 = new CheckingAccount(100, 2.5M);

Console.WriteLine("The intial balance of account 4 is {0:C}", acc4.Balance);

acc4.Credit(100);

acc4.Debit(70);

Console.WriteLine("The final balance of account 4 is {0:C}", acc4.Balance);

Console.ReadKey();

}

1 Reply

Know the answer? Post it — somebody with the same question will find it here.

Vulpes13y ago
Accepted answer
Try:

using System;

public class Account
{
decimal balance;

public decimal Balance
{
get { return balance; }
set
{
if (value >= 0.0M)
{
balance = value;
}
else
{
balance = 0.0M;
Console.WriteLine("Initial balance was invalid. Zero used");
}
}
}

public Account(decimal balance)
{
Balance = balance;
}

public virtual void Credit(decimal amount)
{
balance += amount;
}

public virtual bool Debit(decimal amount)
{
if (amount <= balance)
{
balance -= amount;
return true;
}
else
{
Console.WriteLine("Debit amount exceeded account balance");
return false;
}
}

}

public class SavingsAccount : Account
{
decimal interestRate;

public SavingsAccount(decimal balance, decimal interestRate) : base(balance)
{
this.interestRate = interestRate;
}

public decimal CalculateInterest()
{
return Balance * interestRate / 100m;
}
}

public class CheckingAccount : Account
{
decimal fee;

public CheckingAccount(decimal balance, decimal fee) : base(balance)
{
this.fee = fee;
}

public override void Credit(decimal amount)
{
base.Credit(amount);
Balance -= fee;
}

public override bool Debit(decimal amount)
{
if(base.Debit(amount))
{
Balance -= fee;
return true;
}
else
{
return false;
}
}

}
class Program
{
static void Main()
{
Account acc1 = new Account(100);
Console.WriteLine("The intial balance of account 1 is {0:C}", acc1.Balance);
acc1.Credit(100);
acc1.Debit(50);
Console.WriteLine("The final balance of account 1 is {0:C}", acc1.Balance);
Console.WriteLine();
Account acc2 = new Account(-100);
Console.WriteLine("The intial balance of account 2 is {0:C}", acc2.Balance);
acc2.Credit(30);
acc2.Debit(40);
Console.WriteLine("The final balance of account 2 is {0:C}", acc2.Balance);
Console.WriteLine();

SavingsAccount acc3 = new SavingsAccount(100, 5);
Console.WriteLine("The intial balance of account 3 is {0:C}", acc3.Balance);
acc3.Credit(200);
acc3.Debit(40);
Console.WriteLine("The current balance of account 3 is {0:C}", acc3.Balance);
decimal interest = acc3.CalculateInterest();
acc3.Credit(interest);
Console.WriteLine("The final balance of account 3 is {0:C}", acc3.Balance);
Console.WriteLine();

CheckingAccount acc4 = new CheckingAccount(100, 2.5M);
Console.WriteLine("The intial balance of account 4 is {0:C}", acc4.Balance);
acc4.Credit(100);
acc4.Debit(70);
Console.WriteLine("The final balance of account 4 is {0:C}", acc4.Balance);

Console.ReadKey();
}
}