1  import java.util.HashSet;

  2  import java.util.Set;

  3  

  4  /**

  5     This program prints hash codes of countries.

  6  */

  7  public class HashCodePrinter

  8  {

  9     public static void main(String[] args)

 10     {

 11        Country country1 = new Country("Belgium", 30510);

 12        Country country2 = new Country("Thailand", 514000);

 13        Country country3 = new Country("Belgium", 30510);

 14  

 15        System.out.println("hash code of country1=" + country1.hashCode());

 16        System.out.println("hash code of country2=" + country2.hashCode());

 17        System.out.println("hash code of country3=" + country3.hashCode());

 18  

 19        // Add the countries to the hash set. 

 20  

 21        Set<Country> countries = new HashSet<Country>();

 22        countries.add(country1);

 23        countries.add(country2);

 24        countries.add(country3);

 25  

 26        // Print the set. Note that the set has two elements.

 27  

 28        System.out.println(countries);

 29     }

 30  }