The java.util.ArrayDeque.poll() method in Java is used to retrieve or fetch and remove the element present at the head of the Deque. The peek() method only retrieved the element at the head but the poll() also removes the element along with the retrieval. It returns NULL if the deque is empty.
Parameters: The method does not take any parameter.
Return Value: The method removes the element at the head of the Deque and returns the same. It returns NULL if the deque is empty.
Below programs illustrate the Java.util.ArrayDeque.poll() method:
ArrayDeque: [Welcome, To, Geeks, 4, Geeks] The element at head is: Welcome ArrayDeque after operation: [To, Geeks, 4, Geeks]
ArrayDeque: [10, 15, 30, 20, 5] The element at head is: 10 ArrayDeque after operation: [15, 30, 20, 5]
Program 3: For an empty deque:
ArrayDeque:  The element at head is: null
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