AbstractQueue remove() method in Java with examples

The remove() method of AbstractQueue returns and removes the head of this queue.

Syntax:

public E remove()

Parameters: This method does not accept any parameters.

Returns: The method returns the head of the Queue.

Exception: The function throws an NoSuchElementException if the queue is empty.

Below programs illustrate remove() method:

Program 1:

// Java program to illustrate the
// AbstractQueue remove() method
import java.util.*;
import java.util.concurrent.LinkedBlockingQueue;

public class GFG1 {
    public static void main(String[] argv)
        throws Exception
    {
        // Creating object of AbstractQueue<Integer>
        AbstractQueue<Integer>
            AQ1 = new LinkedBlockingQueue<Integer>();

        // Populating AQ1
        AQ1.add(10);
        AQ1.add(20);
        AQ1.add(30);
        AQ1.add(40);
        AQ1.add(50);

        // print AQ
        System.out.println("AbstractQueue1 contains : " + AQ1);

        // retrieves the head
        int head = AQ1.remove();
        System.out.println("head : " + head);

        // print AQ
        System.out.println("AbstractQueue1 after removal of head : " + AQ1);
    }
}

Output:

AbstractQueue1 contains : [10, 20, 30, 40, 50]
head : 10
AbstractQueue1 after removal of head : [20, 30, 40, 50]

Program 2:

// Java program to illustrate the
// AbstractQueue element() method
// NoSuchElementException
// Java program to illustrate the
// AbstractQueue remove() method
import java.util.*;
import java.util.concurrent.LinkedBlockingQueue;

public class GFG1 {
    public static void main(String[] argv)
        throws Exception
    {
        try {
            // Creating object of AbstractQueue<Integer>
            AbstractQueue<Integer>
                AQ1 = new LinkedBlockingQueue<Integer>();

            // Populating AQ1
            AQ1.add(10);

            // print AQ
            System.out.println("AbstractQueue1 contains : " + AQ1);

            // retrieves the head
            int head = AQ1.remove();
            System.out.println("head : " + head);

            // retrieves the head again
            head = AQ1.remove();
            System.out.println("head : " + head);
        }
        catch (Exception e) {
            System.out.println("Exception: " + e);
        }
    }
}

Output:

AbstractQueue1 contains : [10]
head : 10
Exception: java.util.NoSuchElementException

Reference: https://docs.oracle.com/javase/8/docs/api/java/util/AbstractQueue.html#remove–