import java.util.*; public class SetPractice { public static void main(String[] args) { Set s = new HashSet(); s.add("Mary"); s.add("Joan"); s.add("Mary"); //duplicate! s.add("Dennis"); s.add("Bob"); s.add("MaryAnn"); s.add("Zoe"); System.out.println("Size: " + s.size()); Iterator it = s.iterator(); //iterator while(it.hasNext()) System.out.print(it.next() + " "); System.out.println(); Set t = new TreeSet(s);//from HashSet to TreeSet for( String str : t ) //for-each System.out.print( str + " " ); System.out.println(); //<-----place breakpoint here System.out.println(s); //print any Collection--wow! System.out.println(t); } } /****************** Size: 3 Joan Mary Dennis Dennis Joan Mary [Joan, Mary, Dennis] [Dennis, Joan, Mary] ************************/