Added in [API level 35](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Summary: [Methods](https://developer.android.com/reference/java/util/SequencedSet#pubmethods) \| [Inherited Methods](https://developer.android.com/reference/java/util/SequencedSet#inhmethods)

# SequencedSet

` public interface SequencedSet `   
` implements https://developer.android.com/reference/java/util/SequencedCollection<E>, https://developer.android.com/reference/java/util/Set<E> `

|---|
| java.util.SequencedSet\<E\> |

Known indirect subclasses [ConcurrentSkipListSet](https://developer.android.com/reference/java/util/concurrent/ConcurrentSkipListSet)\<E\>, [LinkedHashSet](https://developer.android.com/reference/java/util/LinkedHashSet)\<E\>, [NavigableSet](https://developer.android.com/reference/java/util/NavigableSet)\<E\>, [SortedSet](https://developer.android.com/reference/java/util/SortedSet)\<E\>, [TreeSet](https://developer.android.com/reference/java/util/TreeSet)\<E\> [ConcurrentSkipListSet](https://developer.android.com/reference/java/util/concurrent/ConcurrentSkipListSet)\<E\> A scalable concurrent `https://developer.android.com/reference/java/util/NavigableSet` implementation based on a `https://developer.android.com/reference/java/util/concurrent/ConcurrentSkipListMap`. [LinkedHashSet](https://developer.android.com/reference/java/util/LinkedHashSet)\<E\> Hash table and linked list implementation of the `Set` interface, with well-defined encounter order.
[NavigableSet](https://developer.android.com/reference/java/util/NavigableSet)\<E\> A `https://developer.android.com/reference/java/util/SortedSet` extended with navigation methods reporting closest matches for given search targets. [SortedSet](https://developer.android.com/reference/java/util/SortedSet)\<E\> A `https://developer.android.com/reference/java/util/Set` that further provides a *total ordering* on its elements. [TreeSet](https://developer.android.com/reference/java/util/TreeSet)\<E\> A `https://developer.android.com/reference/java/util/NavigableSet` implementation based on a `https://developer.android.com/reference/java/util/TreeMap`.   

*** ** * ** ***

A collection that is both a `https://developer.android.com/reference/java/util/SequencedCollection` and a `https://developer.android.com/reference/java/util/Set`. As such, it can be thought of either as a `Set` that also has a well-defined [encounter order](https://developer.android.com/reference/java/util/SequencedCollection#encounter), or as a `SequencedCollection` that also has unique elements.

This interface has the same requirements on the `equals` and `hashCode` methods as defined by `https://developer.android.com/reference/java/util/Set#equals(java.lang.Object)` and `https://developer.android.com/reference/java/util/Set#hashCode()`. Thus, a `Set` and a `SequencedSet` will compare equals if and only if they have equal elements, irrespective of ordering.

`SequencedSet` defines the `https://developer.android.com/reference/java/util/SequencedSet#reversed()` method, which provides a reverse-ordered [view](https://developer.android.com/reference/java/util/Collection#view) of this set. The only difference from the `https://developer.android.com/reference/java/util/SequencedCollection#reversed()` method is that the return type of `SequencedSet.reversed` is `SequencedSet`.

This class is a member of the [Java Collections Framework](https://reference/java/util/package-summary.html#CollectionsFramework).

## Summary

| ### Public methods ||
|---|---|
| ` abstract https://developer.android.com/reference/java/util/SequencedSet<E>` | ` https://developer.android.com/reference/java/util/SequencedSet#reversed()() ` Returns a reverse-ordered [view](https://developer.android.com/reference/java/util/Collection#view) of this collection. |

### Inherited methods

From interface ` https://developer.android.com/reference/java/util/SequencedCollection ` ` default void` ` https://developer.android.com/reference/java/util/SequencedCollection#addFirst(E)(E e) `

Adds an element as the first element of this collection (optional operation).
` default void` ` https://developer.android.com/reference/java/util/SequencedCollection#addLast(E)(E e) `

Adds an element as the last element of this collection (optional operation).
` default E` ` https://developer.android.com/reference/java/util/SequencedCollection#getFirst()() `

Gets the first element of this collection.
` default E` ` https://developer.android.com/reference/java/util/SequencedCollection#getLast()() `

Gets the last element of this collection.
` default E` ` https://developer.android.com/reference/java/util/SequencedCollection#removeFirst()() `

Removes and returns the first element of this collection (optional operation).
` default E` ` https://developer.android.com/reference/java/util/SequencedCollection#removeLast()() `

Removes and returns the last element of this collection (optional operation).
` abstract https://developer.android.com/reference/java/util/SequencedCollection<E>` ` https://developer.android.com/reference/java/util/SequencedCollection#reversed()() `

Returns a reverse-ordered [view](https://developer.android.com/reference/java/util/Collection#view) of this collection.
From interface ` https://developer.android.com/reference/java/util/Set ` ` abstract boolean` ` https://developer.android.com/reference/java/util/Set#add(E)(E e) `

Adds the specified element to this set if it is not already present (optional operation).
` abstract boolean` ` https://developer.android.com/reference/java/util/Set#addAll(java.util.Collection<?%20extends%20E>)(https://developer.android.com/reference/java/util/Collection<? extends E> c) `

Adds all of the elements in the specified collection to this set if they're not already present (optional operation).
` abstract void` ` https://developer.android.com/reference/java/util/Set#clear()() `

Removes all of the elements from this set (optional operation).
` abstract boolean` ` https://developer.android.com/reference/java/util/Set#contains(java.lang.Object)(https://developer.android.com/reference/java/lang/Object o) `

Returns `true` if this set contains the specified element.
` abstract boolean` ` https://developer.android.com/reference/java/util/Set#containsAll(java.util.Collection<?>)(https://developer.android.com/reference/java/util/Collection<?> c) `

Returns `true` if this set contains all of the elements of the specified collection.
` static <E> https://developer.android.com/reference/java/util/Set<E>` ` https://developer.android.com/reference/java/util/Set#copyOf(java.util.Collection<?%20extends%20E>)(https://developer.android.com/reference/java/util/Collection<? extends E> coll) `

Returns an [unmodifiable Set](https://developer.android.com/reference/java/util/SequencedSet#unmodifiable) containing the elements of the given Collection.
` abstract boolean` ` https://developer.android.com/reference/java/util/Set#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object o) `

Compares the specified object with this set for equality.
` abstract int` ` https://developer.android.com/reference/java/util/Set#hashCode()() `

Returns the hash code value for this set.
` abstract boolean` ` https://developer.android.com/reference/java/util/Set#isEmpty()() `

Returns `true` if this set contains no elements.
` abstract https://developer.android.com/reference/java/util/Iterator<E>` ` https://developer.android.com/reference/java/util/Set#iterator()() `

Returns an iterator over the elements in this set.
` static <E> https://developer.android.com/reference/java/util/Set<E>` ` https://developer.android.com/reference/java/util/Set#of(E,%20E,%20E)(E e1, E e2, E e3) `

Returns an unmodifiable set containing three elements.
` static <E> https://developer.android.com/reference/java/util/Set<E>` ` https://developer.android.com/reference/java/util/Set#of(E,%20E,%20E,%20E,%20E,%20E,%20E,%20E,%20E)(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9) `

Returns an unmodifiable set containing nine elements.
` static <E> https://developer.android.com/reference/java/util/Set<E>` ` https://developer.android.com/reference/java/util/Set#of(E,%20E,%20E,%20E,%20E)(E e1, E e2, E e3, E e4, E e5) `

Returns an unmodifiable set containing five elements.
` static <E> https://developer.android.com/reference/java/util/Set<E>` ` https://developer.android.com/reference/java/util/Set#of(E,%20E,%20E,%20E,%20E,%20E)(E e1, E e2, E e3, E e4, E e5, E e6) `

Returns an unmodifiable set containing six elements.
` static <E> https://developer.android.com/reference/java/util/Set<E>` ` https://developer.android.com/reference/java/util/Set#of(E,%20E,%20E,%20E,%20E,%20E,%20E,%20E)(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8) `

Returns an unmodifiable set containing eight elements.
` static <E> https://developer.android.com/reference/java/util/Set<E>` ` https://developer.android.com/reference/java/util/Set#of(E[])(E... elements) `

Returns an unmodifiable set containing an arbitrary number of elements.
` static <E> https://developer.android.com/reference/java/util/Set<E>` ` https://developer.android.com/reference/java/util/Set#of()() `

Returns an unmodifiable set containing zero elements.
` static <E> https://developer.android.com/reference/java/util/Set<E>` ` https://developer.android.com/reference/java/util/Set#of(E,%20E,%20E,%20E,%20E,%20E,%20E,%20E,%20E,%20E)(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9, E e10) `

Returns an unmodifiable set containing ten elements.
` static <E> https://developer.android.com/reference/java/util/Set<E>` ` https://developer.android.com/reference/java/util/Set#of(E,%20E)(E e1, E e2) `

Returns an unmodifiable set containing two elements.
` static <E> https://developer.android.com/reference/java/util/Set<E>` ` https://developer.android.com/reference/java/util/Set#of(E,%20E,%20E,%20E,%20E,%20E,%20E)(E e1, E e2, E e3, E e4, E e5, E e6, E e7) `

Returns an unmodifiable set containing seven elements.
` static <E> https://developer.android.com/reference/java/util/Set<E>` ` https://developer.android.com/reference/java/util/Set#of(E,%20E,%20E,%20E)(E e1, E e2, E e3, E e4) `

Returns an unmodifiable set containing four elements.
` static <E> https://developer.android.com/reference/java/util/Set<E>` ` https://developer.android.com/reference/java/util/Set#of(E)(E e1) `

Returns an unmodifiable set containing one element.
` abstract boolean` ` https://developer.android.com/reference/java/util/Set#remove(java.lang.Object)(https://developer.android.com/reference/java/lang/Object o) `

Removes the specified element from this set if it is present (optional operation).
` abstract boolean` ` https://developer.android.com/reference/java/util/Set#removeAll(java.util.Collection<?>)(https://developer.android.com/reference/java/util/Collection<?> c) `

Removes from this set all of its elements that are contained in the specified collection (optional operation).
` abstract boolean` ` https://developer.android.com/reference/java/util/Set#retainAll(java.util.Collection<?>)(https://developer.android.com/reference/java/util/Collection<?> c) `

Retains only the elements in this set that are contained in the specified collection (optional operation).
` abstract int` ` https://developer.android.com/reference/java/util/Set#size()() `

Returns the number of elements in this set (its cardinality).
` default https://developer.android.com/reference/java/util/Spliterator<E>` ` https://developer.android.com/reference/java/util/Set#spliterator()() `

Creates a `Spliterator` over the elements in this set.
` abstract https://developer.android.com/reference/java/lang/Object` ` https://developer.android.com/reference/java/util/Set#toArray()() `

Returns an array containing all of the elements in this set.
` abstract <T> T[]` ` https://developer.android.com/reference/java/util/Set#toArray(T[])(T[] a) `

Returns an array containing all of the elements in this set; the runtime type of the returned array is that of the specified array.
From interface ` https://developer.android.com/reference/java/util/Collection ` ` abstract boolean` ` https://developer.android.com/reference/java/util/Collection#add(E)(E e) `

Ensures that this collection contains the specified element (optional operation).
` abstract boolean` ` https://developer.android.com/reference/java/util/Collection#addAll(java.util.Collection<?%20extends%20E>)(https://developer.android.com/reference/java/util/Collection<? extends E> c) `

Adds all of the elements in the specified collection to this collection (optional operation).
` abstract void` ` https://developer.android.com/reference/java/util/Collection#clear()() `

Removes all of the elements from this collection (optional operation).
` abstract boolean` ` https://developer.android.com/reference/java/util/Collection#contains(java.lang.Object)(https://developer.android.com/reference/java/lang/Object o) `

Returns `true` if this collection contains the specified element.
` abstract boolean` ` https://developer.android.com/reference/java/util/Collection#containsAll(java.util.Collection<?>)(https://developer.android.com/reference/java/util/Collection<?> c) `

Returns `true` if this collection contains all of the elements in the specified collection.
` abstract boolean` ` https://developer.android.com/reference/java/util/Collection#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object o) `

Compares the specified object with this collection for equality.
` abstract int` ` https://developer.android.com/reference/java/util/Collection#hashCode()() `

Returns the hash code value for this collection.
` abstract boolean` ` https://developer.android.com/reference/java/util/Collection#isEmpty()() `

Returns `true` if this collection contains no elements.
` abstract https://developer.android.com/reference/java/util/Iterator<E>` ` https://developer.android.com/reference/java/util/Collection#iterator()() `

Returns an iterator over the elements in this collection.
` default https://developer.android.com/reference/java/util/stream/Stream<E>` ` https://developer.android.com/reference/java/util/Collection#parallelStream()() `

Returns a possibly parallel `Stream` with this collection as its source.
` abstract boolean` ` https://developer.android.com/reference/java/util/Collection#remove(java.lang.Object)(https://developer.android.com/reference/java/lang/Object o) `

Removes a single instance of the specified element from this collection, if it is present (optional operation).
` abstract boolean` ` https://developer.android.com/reference/java/util/Collection#removeAll(java.util.Collection<?>)(https://developer.android.com/reference/java/util/Collection<?> c) `

Removes all of this collection's elements that are also contained in the specified collection (optional operation).
` default boolean` ` https://developer.android.com/reference/java/util/Collection#removeIf(java.util.function.Predicate<?%20super%20E>)(https://developer.android.com/reference/java/util/function/Predicate<? super E> filter) `

Removes all of the elements of this collection that satisfy the given predicate (optional operation).
` abstract boolean` ` https://developer.android.com/reference/java/util/Collection#retainAll(java.util.Collection<?>)(https://developer.android.com/reference/java/util/Collection<?> c) `

Retains only the elements in this collection that are contained in the specified collection (optional operation).
` abstract int` ` https://developer.android.com/reference/java/util/Collection#size()() `

Returns the number of elements in this collection.
` default https://developer.android.com/reference/java/util/Spliterator<E>` ` https://developer.android.com/reference/java/util/Collection#spliterator()() `

Creates a `https://developer.android.com/reference/java/util/Spliterator` over the elements in this collection.
` default https://developer.android.com/reference/java/util/stream/Stream<E>` ` https://developer.android.com/reference/java/util/Collection#stream()() `

Returns a sequential `Stream` with this collection as its source.
` abstract <T> T[]` ` https://developer.android.com/reference/java/util/Collection#toArray(T[])(T[] a) `

Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.
` abstract https://developer.android.com/reference/java/lang/Object` ` https://developer.android.com/reference/java/util/Collection#toArray()() `

Returns an array containing all of the elements in this collection.
` default <T> T[]` ` https://developer.android.com/reference/java/util/Collection#toArray(java.util.function.IntFunction<T[]>)(https://developer.android.com/reference/java/util/function/IntFunction<T[]> generator) `

Returns an array containing all of the elements in this collection, using the provided `generator` function to allocate the returned array.
From interface ` https://developer.android.com/reference/java/lang/Iterable ` ` default void` ` https://developer.android.com/reference/java/lang/Iterable#forEach(java.util.function.Consumer<?%20super%20T>)(https://developer.android.com/reference/java/util/function/Consumer<? super T> action) `

Performs the given action for each element of the `Iterable` until all elements have been processed or the action throws an exception.
` abstract https://developer.android.com/reference/java/util/Iterator<E>` ` https://developer.android.com/reference/java/lang/Iterable#iterator()() `

Returns an iterator over elements of type `T`.
` default https://developer.android.com/reference/java/util/Spliterator<E>` ` https://developer.android.com/reference/java/lang/Iterable#spliterator()() `

Creates a `https://developer.android.com/reference/java/util/Spliterator` over the elements described by this `Iterable`.

## Public methods

### reversed

Added in [API level 35](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public abstract SequencedSet<E> reversed ()
```

Returns a reverse-ordered [view](https://developer.android.com/reference/java/util/Collection#view) of this collection. The encounter order of elements in the returned view is the inverse of the encounter order of elements in this collection. The reverse ordering affects all order-sensitive operations, including those on the view collections of the returned view. If the collection implementation permits modifications to this view, the modifications "write through" to the underlying collection. Changes to the underlying collection might or might not be visible in this reversed view, depending upon the implementation.

<br />

| Returns ||
|---|---|
| `https://developer.android.com/reference/java/util/SequencedSet<E>` | a reverse-ordered view of this collection, as a `SequencedSet` <br /> |