Iterator vs ListIterator

Iterator	ListIterator
Iterator is used for traversing List and Set both.	We can use ListIterator to traverse List only, we cannot traverse Set using ListIterator.
We can traverse in only forward direction using Iterator.	Using ListIterator, we can traverse a List in both the directions (forward and Backward).
We cannot obtain indexes while using Iterator.	We can obtain indexes at any point of time while traversing a list using ListIterator. The methods nextIndex() and previousIndex() are used for this purpose.
We cannot add element to collection while traversing it using Iterator, it throws ConcurrentModificationException when you try to do it.	We can add element at any point of time while traversing a list using ListIterator.
We cannot replace the existing element value when using Iterator.	By using set(E e) method of ListIterator, we can replace the last element returned by next() or previous() methods.
Methods of Iterator: hasNext() next() remove()	Methods of ListIterator: add(E e) hasNext() hasPrevious() next() nextIndex() previous() previousIndex() remove() set(E e)

package com.collection;

import java.util.ArrayList;

import java.util.Iterator;

import java.util.List;

import java.util.ListIterator;

public class IteratorVsListIterator {

       public static void main(String[] args) {

              List<String> list = new ArrayList<String>();

              list.add("rajesh");

              list.add("sattu");

              list.add("shan");

              System.out.println("iterator :");

              Iterator<String> iterator = list.iterator();

              while (iterator.hasNext()) {

                     System.out.println(iterator.next());

                    

              }

             

             

              ListIterator<String> listItr = list.listIterator();

             

              System.out.println("List Iterator : next");

              while (listItr.hasNext()) {

                     System.out.println(listItr.next());

                     listItr.add("rahul");

              }

             

              System.out.println("List Iterator : previous");

              while (listItr.hasPrevious()) {

                     System.out.println(listItr.previous()); 

              }

       }

}