Java Tutorial/Collections/ListIterator

Add or insert an element to ArrayList using Java ListIterator

   <source lang="java">

import java.util.ArrayList; import java.util.ListIterator; public class Main {

 public static void main(String[] args) {
   ArrayList<String> aList = new ArrayList<String>();
   aList.add("1");
   aList.add("2");
   aList.add("3");
   aList.add("4");
   aList.add("5");
   ListIterator<String> listIterator = aList.listIterator();
   listIterator.next();
   listIterator.add("Added Element");
   for (String str: aList){
     System.out.println(str);
   }
 }

}</source>

Get Previous and next index using Java ListIterator

   <source lang="java">

import java.util.ArrayList; import java.util.ListIterator; public class Main {

 public static void main(String[] args) {
   ArrayList<String> aList = new ArrayList<String>();
   aList.add("1");
   aList.add("2");
   aList.add("3");
   aList.add("4");
   aList.add("5");
   ListIterator<String> listIterator = aList.listIterator();
   System.out.println("Previous: " + listIterator.previousIndex());
   System.out.println("Next: " + listIterator.nextIndex());
   // advance current position by one using next method
   listIterator.next();
   System.out.println("Previous: " + listIterator.previousIndex());
   System.out.println("Next: " + listIterator.nextIndex());
 }

}</source>

Iterate through elements ArrayList using ListIterator

   <source lang="java">

import java.util.ArrayList; import java.util.ListIterator; public class Main {

 public static void main(String[] args) {
   ArrayList<String> arrayList = new ArrayList<String>();
   arrayList.add("1");
   arrayList.add("2");
   arrayList.add("3");
   arrayList.add("4");
   arrayList.add("5");
   ListIterator itr = arrayList.listIterator();
   System.out.println("in forward direction");
   while (itr.hasNext()) {
     System.out.println(itr.next());
   }
   System.out.println("in backward direction");
   while (itr.hasPrevious()) {
     System.out.println(itr.previous());
   }
 }

} /*in forward direction 1 2 3 4 5 in backward direction 5 4 3 2 1

• /</source>

Iterate through elements of Java LinkedList using ListIterator

   <source lang="java">

import java.util.ListIterator; import java.util.LinkedList; public class Main {

 public static void main(String[] args) {
   LinkedList<String> lList = new LinkedList<String>();
   lList.add("1");
   lList.add("2");
   lList.add("3");
   lList.add("4");
   lList.add("5");
   ListIterator itr = lList.listIterator();
   System.out.println("forward direction");
   while (itr.hasNext()){
     System.out.println(itr.next());
   }
   System.out.println("reverse direction");
   while (itr.hasPrevious()){
     System.out.println(itr.previous());
   }
 }

}</source>

ListIterator: In reverse order

   <source lang="java">

import java.util.LinkedList; import java.util.List; import java.util.ListIterator; public class MainClass {

 public static void main(String[] a) {
   List list = new LinkedList();
   list.add("A");
   list.add("B");
   list.add("C");
   list.add("D");
   ListIterator iter = list.listIterator(list.size());
   while (iter.hasPrevious()) {
     System.out.println(iter.previous());
   }
 }

}</source>

ListIterator: Like an Iterator

   <source lang="java">

import java.util.LinkedList; import java.util.List; import java.util.ListIterator; public class MainClass {

 public static void main(String[] a) {
   List list = new LinkedList();
   list.add("A");
   list.add("B");
   list.add("C");
   list.add("D");
   ListIterator iter = list.listIterator();
   while (iter.hasNext()) {
     System.out.println(iter.next());
   }
 }

}</source>

A
B
C
D

Modifying the list that the iterator came from: add(), remove(), and set()

   <source lang="java">

public void add(Object element) public void remove() public void set(Object element)</source>

D
[A, B, C, a, D]

Remove an element from ArrayList using Java ListIterator

   <source lang="java">

import java.util.ArrayList; import java.util.ListIterator; public class Main {

 public static void main(String[] args) {
   ArrayList<String> aList = new ArrayList<String>();
   aList.add("1");
   aList.add("2");
   aList.add("3");
   aList.add("4");
   aList.add("5");
   // Get an object of ListIterator using listIterator() method
   ListIterator listIterator = aList.listIterator();
   listIterator.next();
   listIterator.next();
   // remove element returned by last next method
   listIterator.remove();
   for (String str: aList){
     System.out.println(str);
   }
 }

}</source>

Replace an element from ArrayList using Java ListIterator

   <source lang="java">

import java.util.ArrayList; import java.util.ListIterator; public class Main {

 public static void main(String[] args) {
   ArrayList<String> aList = new ArrayList<String>();
   aList.add("1");
   aList.add("2");
   aList.add("3");
   aList.add("4");
   aList.add("5");
   ListIterator<String> listIterator = aList.listIterator();
   listIterator.next();
   listIterator.set("100");
   for (String str : aList) {
     System.out.println(str);
   }
 }

}</source>