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() methodimport 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() methodimport 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–
