HashSet | Notion

Modifier and Type	Method and Description
`boolean`	[`add](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#add-E->)([E](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html>) e)`Adds the specified element to this set if it is not already present.
`void`	[`clear](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#clear-->)()`Removes all of the elements from this set.
`Object`	[`clone](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#clone-->)()`Returns a shallow copy of this HashSet instance: the elements themselves are not cloned.
`boolean`	[`contains](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#contains-java.lang.Object->)([Object](<https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html>) o)`Returns true if this set contains the specified element.
`boolean`	[`isEmpty](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#isEmpty-->)()`Returns true if this set contains no elements.
[`Iterator](<https://docs.oracle.com/javase/8/docs/api/java/util/Iterator.html>)<[E](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html>)>`	[`iterator](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#iterator-->)()`Returns an iterator over the elements in this set.
`boolean`	[`remove](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#remove-java.lang.Object->)([Object](<https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html>) o)`Removes the specified element from this set if it is present.
`int`	[`size](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#size-->)()`Returns the number of elements in this set (its cardinality).
[`Spliterator](<https://docs.oracle.com/javase/8/docs/api/java/util/Spliterator.html>)<[E](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html>)>`	[`spliterator](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#spliterator-->)()`Creates a late-binding and fail-fast `Spliterator` over the elements in this set.

Modifier and Type	Method and Description
`boolean`	[`add](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#add-E->)([E](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html>) e)`Adds the specified element to this set if it is not already present.
`void`	[`clear](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#clear-->)()`Removes all of the elements from this set.
`Object`	[`clone](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#clone-->)()`Returns a shallow copy of this HashSet instance: the elements themselves are not cloned.
`boolean`	[`contains](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#contains-java.lang.Object->)([Object](<https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html>) o)`Returns true if this set contains the specified element.
`boolean`	[`isEmpty](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#isEmpty-->)()`Returns true if this set contains no elements.
[`Iterator](<https://docs.oracle.com/javase/8/docs/api/java/util/Iterator.html>)<[E](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html>)>`	[`iterator](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#iterator-->)()`Returns an iterator over the elements in this set.
`boolean`	[`remove](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#remove-java.lang.Object->)([Object](<https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html>) o)`Removes the specified element from this set if it is present.
`int`	[`size](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#size-->)()`Returns the number of elements in this set (its cardinality).
[`Spliterator](<https://docs.oracle.com/javase/8/docs/api/java/util/Spliterator.html>)<[E](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html>)>`	[`spliterator](<https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html#spliterator-->)()`Creates a late-binding and fail-fast `Spliterator` over the elements in this set.