AbstractList iterator() method in Java with Examples

Difficulty Level : Basic
Last Updated : 26 Nov, 2018

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

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