//BankAccount.java source code

/**
 * A bank account has a balance that can be changed by 
 * deposits and withdrawals.
 */
public class BankAccount { 
    
   /** Construct a bank account with a zero balance.
    */
   public BankAccount() {   
     this.balance = 0;
     }

   /** Construct a bank account with a given balance.
    * @param initialBalance the initial balance
    */
   public BankAccount(double initialBalance) {   
     this.balance = initialBalance;
     }

   /** Deposit money into the bank account.
    * @param amount the amount to deposit
    */
   public void deposit(double amount) {  
     double updatedBalance = this.balance + amount;
     this.balance = updatedBalance;
     }

   /**
    * Withdraw money from the bank account.
    * @param amount the amount to withdraw
    */
   public void withdraw(double amount) {   
     double updatedBalance = this.balance - amount;
     this.balance = updatedBalance;
     }

   /**
    * Get the current balance of the bank account.
    * @return the current balance
    */
   public double getBalance() {   
     return this.balance;
     }

   
   
   private double balance;
}