A method that returns a special error code can sometimes cause problems. The caller might...

A method that returns a special error code can sometimes cause problems. The caller might ignore the error code or treat the error code as a valid return value. In this case it is better to throw an exception instead. The following class maintains an account balance and returns a special error code.

public class Account{   private double balance;   private Account()   {      balance = 0;   }   public Account(double initialDeposit)   {      balance = initialDeposit;   }   public double getBalance()   {      return balance;   }   // returns new balance or -1 if error   public double deposit(double amount)   {      if (amount < 0)          balance += amount;      else          return -1; // Code indicating error      return balance;   }   // returns new balance or -1 if invalid amount   public double withdraw(double amount)   {      if ((amount < balance) || (amount<0))          return -1;      else          balance -= amount;      return balance;   }}

Rewrite the class so that it throws appropriate exceptions instead of returning -1 as an error code. Write test code that attempts to withdraw and deposit invalid amounts and catches the exceptions that are thrown.