An Iterator is an interface in Java and we can traverse the elements of a list in a forward direction whereas a ListIterator is an interface that extends the Iterator interface and we can traverse the elements in both forward and backward directions. An Iterator can be used in these collection types like List, Set, and Queue whereas ListIterator can be used in List collection only. The important methods of Iterator interface are hasNext(), next() and remove() whereas important methods of ListIterator interface are add(), hasNext(), hasPrevious() and remove().
Syntax for Iterator
public interface Iterator<E>
Example
import java.util.*; public class IteratorTest { public static void main(String[] args) { List<String> listObject = new ArrayList<String>(); listObject.add("India"); listObject.add("Australia"); listObject.add("England"); listObject.add("Bangladesh"); listObject.add("South Africa"); Iterator it = listObject.iterator(); while (it.hasNext()) { System.out.println(it.next()); } } }
Output
India Australia England Bangladesh South Africa
Syntax for ListIterator
public interface ListIterator<E> extends Iterator<E>
Example
import java.util.*; public class ListIteratorTest { public static void main(String[] args) { List<String> listObject = new ArrayList<String>(); listObject.add("Java"); listObject.add("Selenium"); listObject.add("Python"); listObject.add("Java Script"); listObject.add("Cloud Computing"); ListIterator it = listObject.listIterator(); System.out.println("Iterating the elements in forward direction: "); while (it.hasNext()) { System.out.println(it.next()); } System.out.println("--------------------------------------------"); System.out.println("Iterating the elements in backward direction: "); while (it.hasPrevious()) { System.out.println(it.previous()); } } }
Output
Iterating the elementrs in forward direction: Java Selenium Python Java Script Cloud Computing ----------------------------------------------- Iterating the elements in backward direction: Cloud Computing Java Script Python Selenium Java