This article shows you how to use a ListIterator to add elements to an ArrayList. ListIterator is used to return an iterator on a list of list items. ListIterator() returns an iterator over a list from the start, but listIterator(index) returns an iterator over a list of the specified index.

Syntax:

// listIterator() method returns an iterator over the list from the beginning

ListIterator it = list.listIterator()

// listIterator(index) method returns ans iterator over the list from the given index



ListIterator it = list.listIterator(index);

Return Value: This method returns a list iterator for the elements in that list (in the correct order).

Approach: To add an element to ArrayList using Java ListIterator, the process divided into two parts:

1. Make an iterator.

ListIterator it = list.listIterator()

2. Add element using add() method.

it.add(element)

Below is the implementation of the above approach:

Example 1:

// Java program to add elements to ArrayList using
// ListIterator

import java.util.*;

public class GFG {
	public static void main(String[] args)
	{

		// New empty ArrayList
		List list = new ArrayList<>();

		// Add elements to ArrayList
		list.add(10);
		list.add(20);
		list.add(30);

		// Print ArrayList before add 50
		System.out.println("Before add 50: " + list);

		// ListIterator
		ListIterator it = list.listIterator();

		// iterate ArrayList and add 50 to ArrayList
		while (it.hasNext()) {
			// add 50 to ArrayList
			it.add(50);
			// move iterator
			it.next();
		}

		// Print ArrayList after add 50
		System.out.println("After add 50: " + list);
	}
}

Output

Before add 50: [10, 20, 30]
After add 50: [50, 10, 50, 20, 50, 30]

Example 2:

// Java program to add elements to ArrayList using
// ListIterator

import java.util.*;

public class GFG {
	public static void main(String[] args)
	{

		// New empty ArrayList
		List list = new ArrayList<>();

		// Add elements to ArrayList
		list.add(10);
		list.add(20);
		list.add(30);

		// Print ArrayList before add 50
		System.out.println("Before add 50: " + list);

		// Returns an iterator over the list from the given
		// index
		ListIterator it = list.listIterator(1);

		// iterate ArrayList and add 50 to ArrayList
		while (it.hasNext()) {
			// add 50 to ArrayList
			it.add(50);
			// move iterator
			it.next();
		}

		// Print ArrayList after add 50
		System.out.println("After add 50: " + list);
	}
}

Output

Before add 50: [10, 20, 30]
After add 50: [10, 50, 20, 50, 30]