1  import java.util.HashSet;

  2  import java.util.Set;

  3  

  4  /**

  5     A program that prints hash codes of coins.

  6  */

  7  public class CoinHashCodePrinter

  8  {

  9     public static void main(String[] args)

 10     {

 11        Coin coin1 = new Coin(0.25, "quarter");

 12        Coin coin2 = new Coin(0.25, "quarter");

 13        Coin coin3 = new Coin(0.05, "nickel");

 14  

 15        System.out.println("hash code of coin1=" + coin1.hashCode());

 16        System.out.println("hash code of coin2=" + coin2.hashCode());

 17        System.out.println("hash code of coin3=" + coin3.hashCode());

 18  

 19        Set<Coin> coins = new HashSet<Coin>();

 20        coins.add(coin1);

 21        coins.add(coin2);

 22        coins.add(coin3);

 23  

 24        for (Coin c : coins)

 25           System.out.println(c);

 26     }

 27  }