java.util · java.base · since Java 1.6

NavigableSet

declaration

public interface NavigableSet<E> extends SortedSet<E>

A SortedSet with nearest-match navigation and descending views. TreeSet is the standard implementation.

Key methods

`E ceiling(E e) / floor(E e)`	Least element >= e / greatest element <= e (null if none).
`E higher(E e) / lower(E e)`	Strictly greater / strictly lesser neighbor.
`E pollFirst() / pollLast()`	Retrieve and remove the lowest / highest element.
`NavigableSet<E> descendingSet()`	Reverse-order view over the same elements.
`NavigableSet<E> subSet(E from, boolean fromInc, E to, boolean toInc)`	Range view with inclusive/exclusive endpoints.