1  /**
  2     An account that earns interest at a fixed rate.
  3  */
  4  public class SavingsAccount extends BankAccount
  5  {  
  6     private double interestRate;
  7  
  8     /**
  9        Constructs a bank account with a given interest rate.
 10        @param rate the interest rate
 11     */
 12     public SavingsAccount(double rate) 
 13     {  
 14        interestRate = rate;
 15     }
 16  
 17     /**
 18        Adds the earned interest to the account balance.
 19     */
 20     public void addInterest() 
 21     {  
 22        double interest = getBalance() * interestRate / 100;
 23        deposit(interest); 
 24     }
 25  }