Collection Size in java pgm

Collection Size

import java.util.*;

public class CollectionTest

{

 public static void main(String [] args)

  {  

      System.out.println( "Collection Example!\n" );

      int size;

      HashSet collection = new HashSet ();

      String str1 = "Yellow", str2 = "White", str3 =

      "Green", str4 = "Blue"; 

      Iterator iterator;

      collection.add(str1);   

      collection.add(str2);  

      collection.add(str3);  

      collection.add(str4);

      System.out.print("Collection data: "); 

      iterator = collection.iterator();    

      while (iterator.hasNext()){

         System.out.print(iterator.next() + " "); 

      }

      System.out.println();

      size = collection.size();

      if (collection.isEmpty())

     {

         System.out.println("Collection is empty");

      }

      else

     {

         System.out.println( "Collection size: " + size);

      }

      System.out.println();

   }

}