001 package collections; 002 003 /** 004 * Run through gerbils and make them jump in four ways. 005 * 006 * @author Kristian Torp, torp (at) cs (dot) aau (dot) dk 007 * @version 1.0 008 */ 009 010 import java.util.*; // to use ArrayList 011 012 public class UseArrayList { 013 014 public void forEachLoop(ArrayList<Gerbil> list) { 015 for (Gerbil g : list) 016 g.jump(); 017 } 018 019 public void get(ArrayList<Gerbil> list) { 020 for (int i = 0; i < list.size(); i++) { 021 Gerbil g = list.get(i); 022 g.jump(); 023 } 024 } 025 026 public void useIterator(ArrayList<Gerbil> list) { 027 Iterator<Gerbil> it = list.iterator(); 028 while (it.hasNext()) { 029 Gerbil g = it.next(); 030 g.jump(); 031 } 032 } 033 034 public void useListIterator(ArrayList<Gerbil> list) { 035 ListIterator<Gerbil> it = list.listIterator(); 036 while (it.hasNext()) { 037 Gerbil g = it.next(); 038 g.jump(); 039 } 040 } 041 042 /** 043 * Main method that uses ArrayList and Gerbil objects 044 */ 045 public static void main(String[] args) { 046 ArrayList<Gerbil> gerbils = new ArrayList<Gerbil>(); 047 for(int i = 0; i < 42; i++){ 048 gerbils.add(new Gerbil(i)); 049 } 050 UseArrayList cls = new UseArrayList(); 051 cls.forEachLoop(gerbils); 052 cls.get(gerbils); 053 cls.useIterator(gerbils); 054 cls.useListIterator(gerbils); 055 } 056 }