ConcurrentLinkedQueue iterator() method in Java

The iterator() method of ConcurrentLinkedQueue is used to returns an iterator of the same elements as this ConcurrentLinkedQueue in a proper sequence. The elements returned from this method contains elements in order from first(head) to last(tail). The returned iterator is weakly consistent.

Syntax:

public Iterator iterator()

Returns: This method returns the iterator having same elements as present in ConcurrentLinkedQueue in Proper Sequence.

Below programs illustrate iterator() method of ConcurrentLinkedQueue:

Example 1:

// Java Program Demonstrate iterator()
// method of ConcurrentLinkedQueue

import java.util.concurrent.*;
import java.util.*;

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

        // create an ConcurrentLinkedQueue
        ConcurrentLinkedQueue<String>
            queue = new ConcurrentLinkedQueue<String>();

        // Add String to queue
        queue.add("Aman");
        queue.add("Amar");
        queue.add("Sanjeet");
        queue.add("Rabi");

        // Displaying the existing ConcurrentLinkedQueue
        System.out.println("ConcurrentLinkedQueue :\n" + queue);

        // Call iterator() method
        Iterator iterator = queue.iterator();

        // Print elements of iterator
        System.out.println("\nThe String Values of iterator are:");
        while (iterator.hasNext()) {
            System.out.println(iterator.next());
        }
    }
}

Output:

ConcurrentLinkedQueue :
[Aman, Amar, Sanjeet, Rabi]

The String Values of iterator are:
Aman
Amar
Sanjeet
Rabi

Example 2:

// Java Program Demonstrate iterator()
// method of ConcurrentLinkedQueue

import java.util.concurrent.*;
import java.util.*;

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

        // create an ConcurrentLinkedQueue
        ConcurrentLinkedQueue<Integer>
            queue = new ConcurrentLinkedQueue<Integer>();

        // Add Numbers to queue
        queue.add(4353);
        queue.add(7824);
        queue.add(78249);
        queue.add(8724);

        // Displaying the existing ConcurrentLinkedQueue
        System.out.println("ConcurrentLinkedQueue: " + queue);

        // Call iterator() method
        Iterator values = queue.iterator();

        // Print elements of iterator
        System.out.println("\nThe Numbers of iterator are:");
        while (values.hasNext()) {
            System.out.println(values.next());
        }
    }
}

Output:

ConcurrentLinkedQueue: [4353, 7824, 78249, 8724]

The Numbers of iterator are:
4353
7824
78249
8724

Reference: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ConcurrentLinkedQueue.html#iterator–