The Java.util.ArrayDeque.offerFirst(Object element) method in Java is used to add a specific element at the front of the Deque. The function is similar to the addFirst() method of ArrayDeque in Java.
Syntax:
Array_Deque.offerFirst(Object element)
Parameters: The parameter element is of the type ArrayDeque and refers to the element to be added at the front of the Deque.
Return Value: The function returns True if the element is successfully added into the deque else it returns false.
Exceptions: The method throws NullPointerException if the passed parameter is NULL.
Below programs illustrate the Java.util.ArrayDeque.offerFirst() method:
Program 1: Adding String elements into the Deque.
// Java code to illustrate offerFirst()import java.util.*; public class ArrayDequeDemo { public static void main(String args[]) { // Creating an empty ArrayDeque Deque<String> de_que = new ArrayDeque<String>(); // Use add() method to add elements into the Deque de_que.add("Welcome"); de_que.add("To"); de_que.add("Geeks"); de_que.add("4"); de_que.add("Geeks"); // Displaying the ArrayDeque System.out.println("Initial Deque: " + de_que); // Using offerFirst() to add elements de_que.offerFirst("World"); de_que.offerFirst("Hello"); // Displaying the ArrayDeque System.out.println("Final Deque: " + de_que); }} |
Output:
Initial Deque: [Welcome, To, Geeks, 4, Geeks] Final Deque: [Hello, World, Welcome, To, Geeks, 4, Geeks]
Program 2: Adding Integer elements into the Deque.
// Java code to illustrate offerFirst()import java.util.*; public class ArrayDequeDemo { public static void main(String args[]) { // Creating an empty ArrayDeque Deque<Integer> de_que = new ArrayDeque<Integer>(); // Use add() method to add elements into the Deque de_que.add(10); de_que.add(15); de_que.add(30); de_que.add(20); de_que.add(5); // Displaying the ArrayDeque System.out.println("Initial Deque: " + de_que); // Using offerFirst() to add elements de_que.offerFirst(1658); de_que.offerFirst(2458); // Displaying the ArrayDeque System.out.println("Final Deque: " + de_que); }} |
Output:
Initial Deque: [10, 15, 30, 20, 5] Final Deque: [2458, 1658, 10, 15, 30, 20, 5]
