AbstractQueue remove() method in Java with examples (original) (raw)

Last Updated : 26 Nov, 2018

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:

import java.util.*;

import java.util.concurrent.LinkedBlockingQueue;

public class GFG1 {

`` public static void main(String[] argv)

`` throws Exception

`` {

`` AbstractQueue<Integer>

`` AQ1 = new LinkedBlockingQueue<Integer>();

`` AQ1.add( 10 );

`` AQ1.add( 20 );

`` AQ1.add( 30 );

`` AQ1.add( 40 );

`` AQ1.add( 50 );

`` System.out.println( "AbstractQueue1 contains : " + AQ1);

`` int head = AQ1.remove();

`` System.out.println( "head : " + head);

`` 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:

import java.util.*;

import java.util.concurrent.LinkedBlockingQueue;

public class GFG1 {

`` public static void main(String[] argv)

`` throws Exception

`` {

`` try {

`` AbstractQueue<Integer>

`` AQ1 = new LinkedBlockingQueue<Integer>();

`` AQ1.add( 10 );

`` System.out.println( "AbstractQueue1 contains : " + AQ1);

`` int head = AQ1.remove();

`` System.out.println( "head : " + head);

`` 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–