    01: /**
    02:    A bank account has a balance that can be changed by
    03:    deposits and withdrawals.
    04: */
    05: public class BankAccount
    06: {
    07:    /**
    08:       Constructs a bank account with a zero balance.
    09:    */
    10:    public BankAccount()
    11:    {
    12:       balance = 0;
    13:    }
    14:
    15:    /**
    16:       Constructs a bank account with a given balance.
    17:       @param initialBalance the initial balance
    18:    */
    19:    public BankAccount(double initialBalance)
    20:    {
    21:       balance = initialBalance;
    22:    }
    23:
    24:    /**
    25:       Deposits money into the bank account.
    26:       @param amount the amount to deposit
    27:    */
    28:    public void deposit(double amount)
    29:    {
    30:       double newBalance = balance + amount;
    31:       balance = newBalance;
    32:    }
    33:
    34:    /**
    35:       Withdraws money from the bank account.
    36:       @param amount the amount to withdraw
    37:    */
    38:    public void withdraw(double amount)
    39:    {
    40:       double newBalance = balance - amount;
    41:       balance = newBalance;
    42:    }
    43:
    44:    /**
    45:       Gets the current balance of the bank account.
    46:       @return the current balance
    47:    */
    48:    public double getBalance()
    49:    {
    50:       return balance;
    51:    }
    52:
    53:    private double balance;
    54: }