/**
 * Java Collections Framework > LinkedListExample.java
 *
 * Use a LinkedList to store objects.  A LinkedList grows dynamically as
 * you add objects to it; it also shrinks dynamically when you remove objects
 * from it.  A LinkedList is very similar to an ArrayList; the difference is
 * that LinkedList has an additional set of methods that can get, remove, 
 * and insert at the front and back of the list.  Because of this, a 
 * LinkedList may be used as a stack, queue, or double-ended queue (also
 * known as a deque).
 * 
 * @author Feihong Hsu
 */

import java.util.LinkedList;             // A growable array

public class LinkedListExample {
    
    // This method prints the elements of the given LinkedList.
    public static void printLinkedList(LinkedList list) {
        System.out.print( "LinkedList: " );
        
        // If the list is not empty, print a comma-delimited list of all the 
        // elements.  Otherwise just print "empty".
        if (!list.isEmpty()) {
            for (int i=0; i < list.size(); i++)
                System.out.print( list.get(i) + ", " );
            System.out.println();
        }
        else
            System.out.println( "empty" );
    }
    
    public static void main(String[] args) {
        LinkedList list = new LinkedList();
        
        // Add 5 objects to the LinkedList.
        list.add("Popcorn");
        list.add(new Double(63.0));
        list.add(new StringBuffer("Butter"));
        list.add(new Integer(923));
        list.add(new java.awt.Point(3, 6));
        
        // "LinkedList: Popcorn, 63.0, Butter, 923, java.awt.Point[x=3,y=6]"
        printLinkedList(list);
        
        // Remove the first element from the LinkedList.
        list.removeFirst();
        
        // "LinkedList:  63.0, Butter, 923, java.awt.Point[x=3,y=6],"
        printLinkedList(list);
        
        // Remove the last element from the LinkedList.
        list.removeLast();
        
        // "LinkedList:  63.0, Butter, 923,"
        printLinkedList(list);
        
        // Add an object to the front of the LinkedList.
        list.addFirst(new Long(788L));
        
        // "LinkedList:  788, 63.0, Butter, 923,"
        printLinkedList(list);
        
        // Add an object to the back of the LinkedList.
        list.addLast(new Character('X'));
        
        // "LinkedList:  788, 63.0, Butter, 923, X,"
        printLinkedList(list);
        
        // Print the first element of the LinkedList - "First element: 788"
        System.out.println( "First element: " + list.getFirst() );
        
        // Print the last element of the LinkedList - "Last element: X"
        System.out.println( "Last element: " + list.getLast() );
    }
}

/* Output:

LinkedList: Popcorn, 63.0, Butter, 923, java.awt.Point[x=3,y=6], 
LinkedList: 63.0, Butter, 923, java.awt.Point[x=3,y=6], 
LinkedList: 63.0, Butter, 923, 
LinkedList: 788, 63.0, Butter, 923, 
LinkedList: 788, 63.0, Butter, 923, X, 
First element: 788
Last element: X

*/