- Given a LinkedList collection in java, we would like retain certain elements or nodes of linkedlist.
- We would like to remove rest of elements from linkedlist.
- The LinkedList class extends AbstractSequentialList and implements the List interface.
- LinkedList class have following method to retain elements/ nodes.
- boolean retainAll(Collection<?> c)
Retains only the elements in this list that are contained in the specified collection.
- boolean retainAll(Collection<?> c)
Program – Retain & remove elements/ nodes of linked list in java
package org.learn.collection.list.linkedlist; import java.util.LinkedList; public class DemoRetainInOfLinkedList { public static void main(String[] args) { LinkedList linkedList = new LinkedList<>(); linkedList.add( "squash" ); linkedList.add( "archery" ); linkedList.add( "golf" ); linkedList.add( "judo" ); linkedList.add( "canoe" ); linkedList.add( "squash" ); linkedList.add( "diving" ); linkedList.add( "judo" ); System.out.println( "1. Demo of retain & remove elements - Linkedlist: " ); demoRetainAll(linkedList); } private static void demoRetainAll(LinkedList linkedList) { // [squash, archery, golf, judo, canoe, canoe, diving, squash, bowling, judo] System.out.println( "2. original LinkedList:" + linkedList); LinkedList retainSportsList = new LinkedList<>(); retainSportsList.add( "golf" ); retainSportsList.add( "diving" ); retainSportsList.add( "archery" ); retainSportsList.add( "badminton" ); System.out.println( "3. Elements to be retained:" +retainSportsList); linkedList.retainAll(retainSportsList); //[archery, golf, diving] System.out.println( "4. Elements retained in original linkedlist: " + linkedList); } } |
Output – Retain & remove elements/ nodes of linked list in java
1. Demo of retain & remove elements - Linkedlist: 2. Original LinkedList:[squash, archery, golf, judo, canoe, squash, diving, judo] 3. Elements to be retained:[golf, diving, archery, badminton] 4. Elements retained in original linkedlist: [archery, golf, diving] |