Slide 6.a: Populating and updating a LinkedList

Populating and Updating a LinkedList

It is best to use an ArrayList when:

You want to access random items frequently.
You only need to add or remove elements at the end of the list.

On the other end, it is best to use a LinkedList when:

You only use the list by looping through it instead of accessing random items.
You frequently need to add and remove items from the beginning, middle or end of the list.

LinkList.java (LinkedList being reserved)

 // Java program to populate and update a LinkedList
 import java.util.LinkedList;

 class LinkList {
   // The driver method
   public static void main( String[ ] args ) {
     LinkedList<Integer> numbers = new LinkedList<>( );
     int n     = args.length;
     int index = Integer.parseInt( args[n-2] );
     int value = Integer.parseInt( args[n-1] );

     // Add elements in the linked list.
     for ( int i = 0; i < n-2; i++ )
       numbers.( Integer.parseInt( args[i] ) );
     System.out.println( "LinkedList: " + numbers );

     // Change an element.
     numbers.( index, value );
     System.out.println( "Updated LinkedList: " + numbers );
   }
 }

shell> java LinkList (a list of integers to be inserted)

(index to update) (number to update)