PriorityBlockingQueue iterator() method in Java

The iterator() method of PriorityBlockingQueue class Returns an iterator over the elements in this queue. The elements returned from this method do not follow any order. The returned iterator is weakly consistent.

Syntax:

public Iterator iterator()

Parameter: This method does not take any parameter.

Returns: This method returns an iterator having same elements as present in PriorityBlockingQueue.

Below program illustrate iterator() method of PriorityBlockingQueue.

Example 1:

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

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

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

        // define capacity of PriorityBlockingQueue
        int capacityOfQueue = 5;

        // create object of PriorityBlockingQueue
        PriorityBlockingQueue<Integer> PrioQueue
            = new PriorityBlockingQueue<Integer>(capacityOfQueue);

        // Add elements to PriorityBlockingQueue
        PrioQueue.add(945645);
        PrioQueue.add(6468516);
        PrioQueue.add(7564165);
        PrioQueue.add(45616);

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

        // Call iterator() method of PriorityBlockingQueue
        Iterator iteratorVals = PrioQueue.iterator();

        // Print elements of iterator
        // created from PriorityBlockingQueue
        System.out.println("The iterator values"
                           + " of PriorityBlockingQueue are:");

        while (iteratorVals.hasNext()) {
            System.out.println(iteratorVals.next());
        }
    }
}

Output:

PrioQueue: [45616, 945645, 7564165, 6468516]
The iterator values of PriorityBlockingQueue are:
45616
945645
7564165
6468516

Example 2: To illustrate iterator() method of PriorityBlockingQueue which contains list of names.

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

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

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

        // define capacity of PriorityBlockingQueue
        int capacityOfQueue = 5;

        // create object of PriorityBlockingQueue
        PriorityBlockingQueue<String> names
            = new PriorityBlockingQueue<String>(capacityOfQueue);

        // Add names of students of girls college
        names.add("Geeks");
        names.add("forGeeks");
        names.add("A");
        names.add("Computer");
        names.add("Portal");

        // Call iterator() method of PriorityBlockingQueue
        Iterator iteratorVals = names.iterator();

        // Print elements of iterator
        // created from PriorityBlockingQueue
        System.out.println("The Names are:");

        while (iteratorVals.hasNext()) {
            System.out.println(iteratorVals.next());
        }
    }
}

Output:

The Names are:
A
Computer
Geeks
forGeeks
Portal

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