TreeSet class Methods in Java Part -I

java.util.TreeSet

 A NavigableSet implementation based on a TreeMap.The elements are ordered using their natural ordering, or by a Comparator provided at a set creation time, depending on which constructor is used.

Some methods of TreeSet class.

add(String): This method adds the specified element to this set if it is not already present.

addAll(Collection): This method adds all of the elements in the specified collection to this set.

ceiling(String): This method returns the least element in this set greater than or equal to the given element, or null if there is no such element.

clear(): This method removes all of the elements from this set.

clone(): This method returns a shallow copy of this TreeSet instance.

comparator(): This method returns the comparator used to order the elements in this set,or null if this set uses the natural ordering of its elements.

contains(Object): This method returns true if this set contains the specified element.

descendingIterator(): This method returns an iterator over the elements in this set in descending order.

descendingSet(): This method returns a reverse order view of the elements contained in this set.

first(): This method returns the first (lowest) element currently in this set.

floor(String): This method returns the greatest element in this set less than or equal to the given element, or null if there is no such element.

forEach(Consumer): This method performs the given action for each element of the Iterable until all elements have been processed or the action throws an exception.

headSet(K): This method returns a view of the portion of this set whose elements are strictly less than toElement.

headSet(K, boolean): This method returns a view of the portion of this set whose elements are less than(or equal to, if inclusive is true) toElement.

Some more methods of TreeSet class