see †Collection interface† for descriptions and examples of all of HashSet's methods
■ This class implements the Set Interface, and extends the AbstractSet class.† It is for everyday Set usage.
■ HashSet† is for unordered Sets (with no duplicates allowed) in random or indeterminate order. So you can't control the order here.† i.e. The snippet below will print† 1 3 2† or† 3 2 1, depending on your JVM, not† 1 2 3† which is the order in which the three items were entered.
Set hs = new HashSet( );
System.out.println( hs );†††††
■† HashSetís everyday constructors:
HashSet hs = new HashSet( );† ††††††††††††††††††††††††† creates an empty set
HashSet hs = new HashSet(Collection);† †††††††† creates a set from any Collection