An Deque interface. ArrayDeque can be used as a stack or queue. Null elements are prohibited.
poll methodThe poll method can be used to retrieve and remove the ArrayDeque object.
public E poll()
This method does not take any arguments.
The poll() method retrieves and removes the head of the deque object. If the deque object is empty, then the method returns null.
The code below demonstrates how to use the poll method.
import java.util.ArrayDeque;class Poll {public static void main( String args[] ) {ArrayDeque<String> arrayDeque = new ArrayDeque<>();arrayDeque.add("1");arrayDeque.add("2");arrayDeque.add("3");System.out.println("The arrayDeque is " + arrayDeque);System.out.println("arrayDeque.poll() returns : " + arrayDeque.poll());System.out.println("The arrayDeque is " + arrayDeque);}}
In the code above:
In line 1, we import the ArrayDeque class.
In line 4, we create an ArrayDeque object with the name arrayDeque.
From lines 5 to 7, we use the add() method of the arrayDeque object to add three elements ("1","2","3") to arrayDeque.
In line 10, we use the poll() method of the arrayDeque object to get and remove the head element. In our case, 1 will be removed and returned.