HashSet class « HashSet « Set « Collections

This class implements the Set interface, backed by a hash table (actually a HashMap instance).

Constructor	Summary
HashSet()	Creates a new, empty set; the backing HashMap instance has default initial capacity (16) and load factor (0.75).
HashSet(Collection<? extends E> c)	Creates a new set containing the elements in the specified collection.
HashSet(int initialCapacity)	Creates a new, empty set; the backing HashMap instance has the specified initial capacity and default load factor (0.75).
HashSet(int initialCapacity, float loadFactor)	Creates a new, empty set; the backing HashMap instance has the specified initial capacity and the specified load factor.

Return	Method	Summary
boolean	add(E e)	Adds the specified element to this set if it is not already present.
void	clear()	Removes all of the elements from this set.
Object	clone()	Returns a shallow copy of this HashSet instance: the elements themselves are not cloned.
boolean	contains(Object o)	Returns true if this set contains the specified element.
boolean	isEmpty()	Returns true if this set contains no elements.
Iterator<E>	iterator()	Returns an iterator over the elements in this set.
boolean	remove(Object o)	Removes the specified element from this set if it is present.
int	size()	Returns the number of elements in this set (its cardinality).