Collection Removal in java pgm

Collection Removal

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();

      collection.remove(str2);

      System.out.println("After removing [" + str2 + "]\n");

      System.out.print("Now collection data: ");

      iterator = collection.iterator();    

      while (iterator.hasNext())

      {

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

      }

      System.out.println();

      size = collection.size();

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

   }

}