Question

Ok, so I hope you can all help, I have been tasked whilst tying to learn the language with the age-old test of simple savings account and checking account using inheritence.

My problem is, I want to make the checking account incapable of going over its overdraft limit and the savings account incapable of going below 0 but cant work out how? my code so far is as follows:

SUPERCLASS (BankAccount):

public class BankAccount
    {
        protected String CustomerName;
        protected String AccountNumber;
        protected float Balance;


//Constructor Methods

 public BankAccount(String CustomerNameIn, String AccountNumberIn, float BalanceIn)
        {
            CustomerName = CustomerNameIn;
            AccountNumber = AccountNumberIn;
            Balance = BalanceIn;

        }

      // Get  name
      public String getCustomerName()
        {
            return (CustomerName);
        }

      // Get account number
      public String getAccountNumber()
        {
            return (AccountNumber);
        }

       public float getBalance()
        {
            return (Balance);
        }


        public void Withdraw(float WithdrawAmountIn)
       {  
           if(WithdrawAmountIn < 0)
                System.out.println("Sorry, you can not withdraw a negative amount, if you wish to withdraw money please use the withdraw method");
           else
                Balance = Balance - WithdrawAmountIn;
       }

        public void Deposit(float DepositAmountIn)
       {
           if(DepositAmountIn < 0)
                System.out.println("Sorry, you can not deposit a negative amount, if you wish to withdraw money please use the withdraw method");
           else 
           Balance = Balance + DepositAmountIn;
       }


    } // End Class BankDetails

SUBCLASS (SavingsAccount):

public class SavingsAccount extends BankAccount
  {   

      private float Interest;

      public SavingsAccount(String CustomerNameIn, String AccountNumberIn, float InterestIn, float BalanceIn)
        {
            super (CustomerNameIn, AccountNumberIn, BalanceIn);
            Interest = InterestIn;
        }


      public float getInterestAmount()
       {
           return (Interest);
       }

      public float newBalanceWithInterest()
       {  
           Balance = (getBalance() + (getBalance()  * Interest / 100) );

           return (Balance);
       }

       public void SavingsOverdraft()
       {
            if( Balance < 0)
                System.out.println("Sorry, this account is not permitted to have an overdraft facility");
       }

   }

SUBCLASS (CheckingAccount):

public class CheckingAccount extends BankAccount
  {
      private float Overdraft;


      public CheckingAccount(String CustomerNameIn, String AccountNumberIn, float BalanceIn, float OverdraftIn)
        {

            super (CustomerNameIn, AccountNumberIn, BalanceIn);

            Overdraft = OverdraftIn;
        }

       public float getOverdraftAmount()
       {
           return(Overdraft);
       }

      public void setOverdraft()
        {
            if (Balance < Overdraft)
                System.out.println("Sorry, the overdraft facility on this account cannot exceed £100");

       }
    }

Thank you very very much for any advice and help!

Answer 1

Add getOverdraftAmount() to your base class:

public int getOverdraftAmount() {
    return 0;
}

Then override that method in account subclasses that allow overdrafts. Then revise your logic for withdrawal to take into account that the overdraft limit might not be zero.

public void Withdraw(float WithdrawAmountIn)
   {  
       if(WithdrawAmountIn < 0)
            System.out.println("Sorry, you can not withdraw a negative amount, if you wish to withdraw money please use the withdraw method");
       else if (Balance - WithdrawAmountIn < -getOverdraftAmount()) {
            System.out.println("Sorry, this withdrawal would exceed the overdraft limit");
       else 
            Balance = Balance - WithdrawAmountIn;
   }