The java.util.ArrayDeque.peekFirst() method in Java is used to retrieve or fetch the first element 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 or it is empty, then Null is returned.
Parameters: The method does not take any parameter.
Return Value: The method returns the first element of the Deque.
Below programs illustrate the Java.util.ArrayDeque.peekFirst() method:
Initial ArrayDeque: [Welcome, To, Geeks, 4, Geeks] The first element is: Welcome Final ArrayDeque: [Welcome, To, Geeks, 4, Geeks]
Initial ArrayDeque: [10, 15, 30, 20, 5] The first element is: 10 Final ArrayDeque: [10, 15, 30, 20, 5]
Program 3: For an empty deque:
ArrayDeque:  The first element is: null
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