Iterator and ListIterator

 

package com.jzm.collections;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.ListIterator;
class A{
 
}
public class   IteratorDemo{
 public static void main(String[] args) {
      ArrayList   arrayList = new ArrayList();
 
      arrayList.add("a");
      arrayList.add("b");
      arrayList.add("d");
      arrayList.add("c");
      arrayList.add("e");
      arrayList.add("f");
      arrayList.add("g");   
      Iterator iterator = arrayList.iterator();
      System.out.print("未經處理資料為：");
      while (iterator.hasNext()){
  Object object = (Object) iterator.next(); 
  System.out.print(object+" ");
 }    
      ListIterator lIterator = arrayList.listIterator();
      System.out.println(" 修改的資料為：");
      while (lIterator.hasNext()) {
  Object object = (Object) lIterator.next();
  lIterator.set(object+"+");  
 } 
 
   
      iterator = arrayList.iterator();
      while (iterator.hasNext()){
     Object object = (Object) iterator.next(); 
      System.out.print(object+" ");
   }    
      System.out.println('\n');
      while(lIterator.hasPrevious()){
        Object object = (Object)lIterator.previous(); 
         System.out.print(object+" ");
      }         
 }
}

 

ListIterator  有hashPrevious()方法 而Iterator只有hashNext()