Iterator vs ListIterator in Java?

JavaObject Oriented ProgrammingProgramming

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
raja
Published on 29-Aug-2019 13:39:40
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