HashSet set = new HashSet();
set.add( new Integer( 6 ) );
set.add( new Integer( 1 ) );
set.add( new Integer( 4 ) );
System.out.println( set );
System.out.println();
System.out.println( "Enumerate the HashSet" );
Enumeration e = set.elements();
while ( e.hasMoreElements() )
System.out.println( e.nextElement() );
System.out.println();
System.out.println( "Iterate through the HashSet" );
for ( HashSetIterator i = set.begin(); !i.atEnd(); i.advance() )
System.out.println( i.get() );
System.out.println();
System.out.println( "Show that duplicates cannot be added." );
Object value = set.add( new Integer( 8 ) );
if ( value != null )
System.out.println( "Could not add 8." );
else
{
System.out.println( "Added 8" );
System.out.println( "New contents are " + set );
}
value = set.add( new Integer( 4 ) );
if ( value != null )
System.out.println( "Could not add 4." );
else
{
System.out.println( "Added 4." );
System.out.println( "New contents are " + set );
}
