      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  }