ArrayList iterator() method in Java with Examples

The iterator() method of ArrayList class in Java Collection Framework is used to get an iterator over the elements in this list in proper sequence. The returned iterator is fail-fast.

Syntax:

 Iterator iterator()

Parameter: This method do not accept any parameter.

Return Value: This method returns an iterator over the elements in this list in proper sequence

Below examples illustrate the ArrayList.iterator() method:

Program 1:

// Java code to illustrate iterator()

import java.util.*;

public class GFG {

    public static void main(String[] args)
    {
        // Create and populate the list
        ArrayList<String> list
            = new ArrayList<>();

        list.add("Geeks");
        list.add("for");
        list.add("Geeks");
        list.add("is");
        list.add("a");
        list.add("CS");
        list.add("Students");
        list.add("Portal");

        // Displaying the list
        System.out.println("The list is: \n"
                           + list);

        // Create an iterator for the list
        // using iterator() method
        Iterator<String> iter
            = list.iterator();

        // Displaying the values after iterating
        // through the list
        System.out.println("\nThe iterator values"
                           + " of list are: ");
        while (iter.hasNext()) {
            System.out.print(iter.next() + " ");
        }
    }
}

Output:

The list is: 
[Geeks, for, Geeks, is, a, CS, Students, Portal]

The iterator values of list are: 
Geeks for Geeks is a CS Students Portal

Program 2:

// Java code to illustrate iterator()

import java.util.*;

public class GFG {

    public static void main(String args[])
    {
        // Creating an empty ArrayList
        ArrayList<Integer> list
            = new ArrayList<Integer>();

        // Use add() method to add
        // elements into the list
        list.add(10);
        list.add(15);
        list.add(30);
        list.add(20);
        list.add(5);

        // Displaying the list
        System.out.println("The list is: \n"
                           + list);

        // Create an iterator for the list
        // using iterator() method
        Iterator<Integer> iter = list.iterator();

        // Displaying the values
        // after iterating through the list
        System.out.println("\nThe iterator values"
                           + " of list are: ");
        while (iter.hasNext()) {
            System.out.print(iter.next() + " ");
        }
    }
}

Output:

The list is: 
[10, 15, 30, 20, 5]

The iterator values of list are: 
10 15 30 20 5