What is the ArrayDeque.poll method in Java?
An Deque interface. ArrayDeque can be used as a stack or queue. Null elements are prohibited.
The poll method
The poll method can be used to retrieve and remove the ArrayDeque object.
Syntax
public E poll()
Parameters
This method does not take any arguments.
Return value
The poll() method retrieves and removes the head of the deque object. If the deque object is empty, then the method returns null.
Code
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);}}
Explanation
In the code above:
-
In line 1, we import the
ArrayDequeclass. -
In line 4, we create an
ArrayDequeobject with the namearrayDeque. -
From lines 5 to 7, we use the
add()method of thearrayDequeobject to add three elements ("1","2","3") toarrayDeque. -
In line 10, we use the
poll()method of thearrayDequeobject to get and remove the head element. In our case,1will be removed and returned.
