AbstractList iterator() method in Java with Examples

The iterator() method of java.util.AbstractList class is used to return an iterator over the elements in this list in proper sequence.

This implementation returns a straightforward implementation of the iterator interface, relying on the backing list’s size(), get(int), and remove(int) methods.

Syntax:

public Iterator iterator()

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

Below are the examples to illustrate the iterator() method.

Example 1:

// Java program to demonstrate
// iterator() method
// for Integer value

import java.util.*;

public class GFG1 {
    public static void main(String[] argv)
        throws Exception
    {

        try {

            // Creating object of AbstractList<Integer>
            AbstractList<Integer>
                arrlist1 = new ArrayList<Integer>();

            // Populating arrlist1
            arrlist1.add(10);
            arrlist1.add(20);
            arrlist1.add(30);
            arrlist1.add(40);
            arrlist1.add(50);

            // print arrlist1
            System.out.println("ArrayList : "
                               + arrlist1);

            // creating object of Iterator
            // using iterator() method
            Iterator it = arrlist1.iterator();

            // printing the iterated value
            while (it.hasNext()) {
                System.out.println("Value is : "
                                   + it.next());
            }
        }

        catch (NullPointerException e) {
            System.out.println("Exception thrown : " + e);
        }
    }
}

Output:

ArrayList : [10, 20, 30, 40, 50]
Value is : 10
Value is : 20
Value is : 30
Value is : 40
Value is : 50

Example 2:

// Java program to demonstrate
// iterator() method
// for String value

import java.util.*;

public class GFG1 {
    public static void main(String[] argv)
        throws Exception
    {

        try {

            // Creating object of AbstractList<String>
            AbstractList<String>
                arrlist1 = new ArrayList<String>();

            // Populating arrlist1
            arrlist1.add("A");
            arrlist1.add("B");
            arrlist1.add("C");
            arrlist1.add("D");
            arrlist1.add("E");

            // print arrlist1
            System.out.println("ArrayList : "
                               + arrlist1);

            // creating object of Iterator
            // using iterator() method
            Iterator it = arrlist1.iterator();

            // printing the iterated value
            while (it.hasNext()) {
                System.out.println("Value is : "
                                   + it.next());
            }
        }

        catch (NullPointerException e) {
            System.out.println("Exception thrown : " + e);
        }
    }
}

Output:

ArrayList : [A, B, C, D, E]
Value is : A
Value is : B
Value is : C
Value is : D
Value is : E