ConcurrentLinkedDeque removeLastOccurrence() Method in Java
The java.util.concurrent.ConcurrentLinkedDeque.removeLastOccurrence() method is an in-built method in Java which accepts a parameter and removes the last appearance of that element in the deque. Thus, in case the element is not present in the deque, it remains unchanged. Syntax:
public boolean removeLastOccurrence(Object o)
Parameters: The function accepts an object elem as parameter which denotes the object whose last appearance from the deque is to be removed. Return Value: The function returns true if elem is present in the deque and returns false otherwise. Exception: The function throws NullPointerException if the specified element passed as parameter to the function is null. Below programs illustrate the use of removeLastOccurrence() method :
Java
/* Java program to demonstrate removeLastOccurrence() method of ConcurrentLinkedDeque */ import java.util.concurrent.*; class ConcurrentLinkedDequeDemo { public static void main(String[] args) { ConcurrentLinkedDeque<String> cld = new ConcurrentLinkedDeque<String>(); cld.addFirst("GFG"); cld.addFirst("Beginner"); cld.addFirst("Gfg"); cld.addFirst("gfg"); cld.addFirst("Beginner"); // Displaying the existing LinkedDeque System.out.println("Elements in " + "the LinkedDeque: " + cld); // Remove last occurrence of element cld.removeLastOccurrence("Beginner"); // Displaying the modified LinkedDeque System.out.println("Elements in " + "the LinkedDeque: " + cld); } } |
Elements in the LinkedDeque: [Beginner, gfg, Gfg, Beginner, GFG] Elements in the LinkedDeque: [Beginner, gfg, Gfg, GFG]
Program 2:
Java
/* Java program to demonstrate removeLastOccurrence() method of ConcurrentLinkedDeque */ import java.util.concurrent.*; class ConcurrentLinkedDequeDemo { public static void main(String[] args) { ConcurrentLinkedDeque<Integer> cld = new ConcurrentLinkedDeque<Integer>(); cld.addFirst( 12 ); cld.addFirst( 280 ); cld.addFirst( 1008 ); cld.addFirst( 1050 ); cld.addFirst( 379 ); // Displaying the existing LinkedDeque System.out.println("Elements in " + "the LinkedDeque: " + cld); try { // Remove last occurrence of element cld.removeLastOccurrence( null ); } catch (Exception e) { System.out.println(e); } } } |
Elements in the LinkedDeque: [379, 1050, 1008, 280, 12] java.lang.NullPointerException
Reference:https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ConcurrentLinkedDeque.html#removeLastOccurrence()