The java.util.ArrayDeque.peek() method in Java is used to retrieve or fetch the element at the head of the Deque. The element retrieved does not get deleted or removed from the Queue instead the method just returns it. If no element is present in the deque then Null is returned.
Parameters: The method does not take any parameter.
Return Value: The method returns the element at the head of the Deque.
Below programs illustrate the Java.util.ArrayDeque.peek() method:
Initial ArrayDeque: [Welcome, To, Geeks, 4, Geeks] The element at head is: Welcome Final ArrayDeque: [Welcome, To, Geeks, 4, Geeks]
Initial ArrayDeque: [10, 15, 30, 20, 5] The element at head is: 10 Final ArrayDeque: [10, 15, 30, 20, 5]
Program 3: For an empty deque:
ArrayDeque:  The element at head is: null
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