import java.util.Iterator; import java.util.TreeSet; public class Main { public static void main(String[] args) { TreeSet<Integer> tSet = new TreeSet<Integer>(); tSet.add(new Integer("1")); tSet.add(new Integer("2")); tSet.add(new Integer("3")); Iterator itr = tSet.iterator(); while (itr.hasNext()){ System.out.println(itr.next()); } } }