LinkedList Class

public class LinkedList extends AbstractSequentialList implements List

ü      A linked-list data structure is a list with each item having a link to the next item.

ü      There can be linear linked lists or circular linked lists.

ü      Linear linked lists end at some point whereas circular linked lists have the last element pointing back to the first element thus forming a circular chain. Extends AbstractSequentialList and implements the List interface.

ü      These operations allow linked lists to be used as a stack, queue.

Constructor

LinkedList()  Constructs an empty list.

LinkedList(Collection<? extends E> c) Constructs a list containing the elements of the specified collection, in the order they are returned by the collection's iterator.

Some Important Methods
void	addFirst(E o) Inserts the given element at the beginning of this list.
void	addLast(E o) Appends the given element to the end of this list.
E	getFirst() Returns the first element in this list.
E	getLast() Returns the last element in this list.
E	removeFirst() Removes and returns the first element from this list.
E	removeLast() Removes and returns the last element from this list.

Example:

import java.util.LinkedList;

public class LinkedListDemo
{

   public static void main(String[] args)
   {

       LinkedList llstStars = new LinkedList();

       llstStars.add("Harry");

       llstStars.add("Emaini");

       llstStars.add("Voldmort");

       llstStars.add("Severes");

       llstStars.add("Dumbuldore");

       System.out.println("Contents of the list :");

       System.out.println(llstStars);

       llstStars.addFirst("Potter");

       llstStars.addLast("Slytherin");

       System.out.println("\nContents of the list after adding Potter and Slytherin :");

       System.out.println(llstStars);

       System.out.println();

       llstStars.remove(2);

       llstStars.remove("Emaini");

       System.out.println("\nContents of the list after deleting Emaini and element at index 2 :");

       System.out.println(llstStars);

       String strTemp = (String) llstStars.get(3);

       llstStars.set(3, strTemp + " snape");

       System.out.println("\nContents of the list after modifying 4th element :");

       System.out.println(llstStars);

   }

}