LinkedList Processing

Objective

In this lab, we will explore and demonstrate LinkedList using built-in methods.

At the end of this lab, learners will have demonstrated the ability to use LinkedList using built-in methods.

Example One: LinkedList Methods

Create a class named LinkedListExample and add the code below:

import java.util.*;
public class LinkedListExample {
     public static void main(String args[]) {

       /* Linked List Declaration */
       LinkedList<String> linkedlist = new LinkedList<String>();

       /*add(String Element) is used for adding
        * the elements to the linked list*/
       linkedlist.add("Item1");
       linkedlist.add("Item5");
       linkedlist.add("Item3");
       linkedlist.add("Item6");
       linkedlist.add("Item2");

       /*Display Linked List Content*/
       System.out.println("Linked List Content: " +linkedlist);

       /*Add First and Last Element*/
       linkedlist.addFirst("First Item");
       linkedlist.addLast("Last Item");
       System.out.println("LinkedList Content after addition: " +linkedlist);

       /*This is how to get and set Values*/
       Object firstvar = linkedlist.get(0);
       System.out.println("First element: " +firstvar);
       linkedlist.set(0, "Changed first item");
       Object firstvar2 = linkedlist.get(0);
       System.out.println("First element after update by set method: " +firstvar2);

       /*Remove first and last element*/
       linkedlist.removeFirst();
       linkedlist.removeLast();
       System.out.println("LinkedList after deletion of first and last element: " +linkedlist);

       /* Add to a Position and remove from a position*/
       linkedlist.add(0, "Newly added item");
       linkedlist.remove(2);
       System.out.println("Final Content: " +linkedlist);
     }
}

Output:

Linked List Content: [Item1, Item5, Item3, Item6, Item2]
LinkedList Content after addition: [First Item, Item1, Item5, Item3, Item6, Item2, Last Item]
First element: First Item
First element after update by set method: Changed first item
LinkedList after deletion of first and last element: [Item1, Item5, Item3, Item6, Item2]
Final Content: [Newly added item, Item1, Item3, Item6, Item2]

Example Two: How to Sort LinkedList

In this example, we will demonstrate how to sort a LinkedList using the Collections.sort() method. Please note that for custom sorting of objects, we can use Collections.sort(linkedList, comparator) method.

Create a class named LinkedListsortExample and add the code below:

public class LinkedListsortExample {
   public static void main(String[] args)
   {
       //Create linked list
       LinkedList<String> linkedList = new LinkedList<>();
       linkedList.add("A");
       linkedList.add("C");
       linkedList.add("B");
       linkedList.add("D");

      //Unsorted
       System.out.println(linkedList);

      //1. Sort the list
       Collections.sort(linkedList);

      //Sorted
       System.out.println(linkedList);

      //2. Custom sorting
       Collections.sort(linkedList, Collections.reverseOrder());

      //Custom sorted
       System.out.println(linkedList);
   }
}

Output:

[A, C, B, D]
[A, B, C, D]
[D, C, B, A]

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GLAB - 303.11.4 - LinkedList Processing.zip

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