java.util.ArrayList Implementation # 2

/*

     ArrayList implementation

     Creating ArrayList of integers

*/

/*

     ArrayList class implements the List interface

     The List interface extends the Collection Interface

*/

import java.util.*;

class Main

{

     public static void main(String args[])

     {

           ArrayList a=new ArrayList();

          

           a.add(new Integer(10));

           a.add(new Integer(18));

           a.add(new Integer(48));

           a.add(new Integer(13));

           a.add(new Integer(56));

           a.add(new Integer(89));

    

           System.out.println();

           System.out.println("The contents of Collection - a are :\n"+a);

           System.out.println();

          

           a.remove(new Integer(18)); // from the Collection Interface

           System.out.println("The contents of Collection - a after deleting \"18\" are :\n"+a);

           System.out.println();

          

           a.remove(3); // from the List Interface

           System.out.println("The contents of Collection - a after deleting 3rd index are :\n"+a);

           System.out.println();

           System.out.println("the size of your collection a is : "+a.size());

          

          

           /* now here finding the sum of all the elements of ArrayList*/

          

           Object arr[]=a.toArray();

           int sum=0;

           for(Object i:arr)

                sum+=(((Integer)i).intValue());

           System.out.println();

           System.out.println("The sum of all the elements of your ArrayList is : "+sum);

     }

}