The java.util.concurrent.ConcurrentLinkedDeque.offerLast() method is an inbuilt method in Java which inserts the specified element, passed as a parameter, to the end of the deque.
Syntax:
Conn_Linked_Deque.offerLast(Object elem)
Parameters: The method accepts a parameter elem which species the element to be inserted to the end of the deque.
Return Value: The function returns True if the element is successfully added into the deque and returns False otherwise.
Exception: The function throws a NullPointerException if the passed parameter is NULL.
Below programs illustrate the ConcurrentLinkedDeque.offerLast() method:
Program 1:
/* Java Program to Demonstrate offerLast()   method of ConcurrentLinkedDeque */  import java.util.concurrent.*;class GFG {    public static void main(String[] args)    {          // Creating an empty Deque        ConcurrentLinkedDeque<String> cld =                        new ConcurrentLinkedDeque<String>();          // Add elements into the Deque        cld.add("Welcome");        cld.add("To");        cld.add("Geeks");        cld.add("4");        cld.add("Geeks");          // Displaying the Deque        System.out.println("Elements in Deque: "                           + cld);          // Displaying the Last element        System.out.println("The Last element is: " +                                       cld.getLast());          /* Insert an element at the tail            of the deque */        if (cld.offerLast("GFG")) {            // Displaying the Last element            System.out.println("The Inserted element is: " +                                               cld.getLast());        }          // Displaying the Deque        System.out.println("Elements in Deque: "                           + cld);          // Displaying the Last element        System.out.println("The Last element is: " +                                       cld.getLast());    }} |
Output:
Elements in Deque: [Welcome, To, Geeks, 4, Geeks] The Last element is: Geeks The Inserted element is: GFG Elements in Deque: [Welcome, To, Geeks, 4, Geeks, GFG] The Last element is: GFG
Program 2:
/* Java Program to Demonstrate offerLast()   method of ConcurrentLinkedDeque */  import java.util.concurrent.*;class GFG {    public static void main(String[] args)    {          // Creating an empty Deque        ConcurrentLinkedDeque<Integer> cld =                   new ConcurrentLinkedDeque<Integer>();          // Add elements into the Deque        cld.add(12);        cld.add(43);        cld.add(29);        cld.add(16);        cld.add(70);          // Displaying the Deque        System.out.println("Elements in Deque: "                           + cld);          // Displaying the Last element        System.out.println("The Last element is: " +                                       cld.getLast());          try {            cld.offerLast(null);        }        catch (Exception e) {            System.out.println(e);        }          /* Insert an element at the tail            of the deque */        if (cld.offerLast(24)) {            // Displaying the Last element            System.out.println("The Inserted element is: "                                          + cld.getLast());        }          // Displaying the Deque        System.out.println("Elements in Deque: "                           + cld);          // Displaying the Last element        System.out.println("The Last element is: " +                                       cld.getLast());    }} |
Output:
Elements in Deque: [12, 43, 29, 16, 70] The Last element is: 70 java.lang.NullPointerException The Inserted element is: 24 Elements in Deque: [12, 43, 29, 16, 70, 24] The Last element is: 24
