# LinkedHashSet

public class **LinkedHashSet** extends [HashSet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/HashSet.html)\<E\>  
implements [Set](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html)\<E\> [Cloneable](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Cloneable.html) [Serializable](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Serializable.html) <br />

Hash table and linked list implementation of the Set interface,
with predictable iteration order. This implementation differs from
HashSet in that it maintains a doubly-linked list running through
all of its entries. This linked list defines the iteration ordering,
which is the order in which elements were inserted into the set
(*insertion-order*). Note that insertion order is *not* affected
if an element is *re-inserted* into the set. (An element e
is reinserted into a set s if s.add(e) is invoked when
s.contains(e) would return true immediately prior to
the invocation.)

This implementation spares its clients from the unspecified, generally
chaotic ordering provided by `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/HashSet.html`, without incurring the
increased cost associated with `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeSet.html`. It can be used to
produce a copy of a set that has the same order as the original, regardless
of the original set's implementation:

```
     void foo(Set s) {
         Set copy = new LinkedHashSet(s);
         ...
     }
 
```
This technique is particularly useful if a module takes a set on input, copies it, and later returns results whose order is determined by that of the copy. (Clients generally appreciate having things returned in the same order they were presented.)

This class provides all of the optional Set operations, and
permits null elements. Like HashSet, it provides constant-time
performance for the basic operations (add, contains and
remove), assuming the hash function disperses elements
properly among the buckets. Performance is likely to be just slightly
below that of HashSet, due to the added expense of maintaining the
linked list, with one exception: Iteration over a LinkedHashSet
requires time proportional to the *size* of the set, regardless of
its capacity. Iteration over a HashSet is likely to be more
expensive, requiring time proportional to its *capacity*.

A linked hash set has two parameters that affect its performance:
*initial capacity* and *load factor*. They are defined precisely
as for HashSet. Note, however, that the penalty for choosing an
excessively high value for initial capacity is less severe for this class
than for HashSet, as iteration times for this class are unaffected
by capacity.

**Note that this implementation is not synchronized.**
If multiple threads access a linked hash set concurrently, and at least
one of the threads modifies the set, it *must* be synchronized
externally. This is typically accomplished by synchronizing on some
object that naturally encapsulates the set.

If no such object exists, the set should be "wrapped" using the
`https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collections.html#synchronizedSet(java.util.Set<T>)`
method. This is best done at creation time, to prevent accidental
unsynchronized access to the set:

```
   Set s = Collections.synchronizedSet(new LinkedHashSet(...));
```

The iterators returned by this class's iterator method are
*fail-fast* : if the set is modified at any time after the iterator
is created, in any way except through the iterator's own remove
method, the iterator will throw a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/ConcurrentModificationException.html`.
Thus, in the face of concurrent modification, the iterator fails quickly
and cleanly, rather than risking arbitrary, non-deterministic behavior at
an undetermined time in the future.

Note that the fail-fast behavior of an iterator cannot be guaranteed
as it is, generally speaking, impossible to make any hard guarantees in the
presence of unsynchronized concurrent modification. Fail-fast iterators
throw ConcurrentModificationException on a best-effort basis.
Therefore, it would be wrong to write a program that depended on this
exception for its correctness: *the fail-fast behavior of iterators should be used only to detect bugs.*

This class is a member of the
[Java Collections Framework](https://developers.google.com/j2objc/javadoc/jre/technotes/guides/collections/index.html).

##### See Also

- `https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#hashCode()`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/HashSet.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeSet.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Hashtable.html`

### Public Constructor Summary

|---|---|
|   | [LinkedHashSet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/LinkedHashSet.html#LinkedHashSet(int,%20float))(int initialCapacity, float loadFactor) Constructs a new, empty linked hash set with the specified initial capacity and load factor. |
|   | [LinkedHashSet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/LinkedHashSet.html#LinkedHashSet(int))(int initialCapacity) Constructs a new, empty linked hash set with the specified initial capacity and the default load factor (0.75). |
|   | [LinkedHashSet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/LinkedHashSet.html#LinkedHashSet())() Constructs a new, empty linked hash set with the default initial capacity (16) and load factor (0.75). |
|   | [LinkedHashSet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/LinkedHashSet.html#LinkedHashSet(java.util.Collection<?%20extends%20E>))([Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<? extends E\> c) Constructs a new linked hash set with the same elements as the specified collection. |

### Public Method Summary

|---|---|
| [Spliterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html)\<E\> | [spliterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/LinkedHashSet.html#spliterator())() Creates a *[late-binding](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator#binding)* and *fail-fast* `Spliterator` over the elements in this set. |

### Inherited Method Summary

From class [java.util.HashSet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/HashSet.html)

|---|---|
| boolean | [add](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/HashSet.html#add(E))(E e) Adds the specified element to this set if it is not already present. |
| void | [clear](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/HashSet.html#clear())() Removes all of the elements from this set. |
| [Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) | [clone](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/HashSet.html#clone())() Returns a shallow copy of this HashSet instance: the elements themselves are not cloned. |
| boolean | [contains](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/HashSet.html#contains(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) o) Returns true if this set contains the specified element. |
| boolean | [isEmpty](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/HashSet.html#isEmpty())() Returns true if this set contains no elements. |
| [Iterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Iterator.html)\<E\> | [iterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/HashSet.html#iterator())() Returns an iterator over the elements in this set. |
| boolean | [remove](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/HashSet.html#remove(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) o) Removes the specified element from this set if it is present. |
| int | [size](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/HashSet.html#size())() Returns the number of elements in this set (its cardinality). |
| [Spliterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html)\<E\> | [spliterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/HashSet.html#spliterator())() Creates a *[late-binding](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator#binding)* and *fail-fast* `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html` over the elements in this set. |

From class [java.util.AbstractSet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractSet.html)

|---|---|
| boolean | [equals](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractSet.html#equals(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) o) Compares the specified object with this set for equality. |
| int | [hashCode](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractSet.html#hashCode())() Returns the hash code value for this set. |
| boolean | [removeAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractSet.html#removeAll(java.util.Collection<?>))([Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<?\> c) Removes from this set all of its elements that are contained in the specified collection (optional operation). |

From class [java.util.AbstractCollection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractCollection.html)

|---|---|
| boolean | [add](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractCollection.html#add(E))(E e) Ensures that this collection contains the specified element (optional operation). This implementation always throws an UnsupportedOperationException. |
| boolean | [addAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractCollection.html#addAll(java.util.Collection<?%20extends%20E>))([Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<? extends E\> c) Adds all of the elements in the specified collection to this collection (optional operation). This implementation iterates over the specified collection, and adds each object returned by the iterator to this collection, in turn. |
| void | [clear](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractCollection.html#clear())() Removes all of the elements from this collection (optional operation). This implementation iterates over this collection, removing each element using the Iterator.remove operation. |
| boolean | [contains](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractCollection.html#contains(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) o) Returns true if this collection contains the specified element. This implementation iterates over the elements in the collection, checking each element in turn for equality with the specified element. |
| boolean | [containsAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractCollection.html#containsAll(java.util.Collection<?>))([Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<?\> c) Returns true if this collection contains all of the elements in the specified collection. This implementation iterates over the specified collection, checking each element returned by the iterator in turn to see if it's contained in this collection. |
| boolean | [isEmpty](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractCollection.html#isEmpty())() Returns true if this collection contains no elements. This implementation returns size() == 0. |
| abstract [Iterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Iterator.html)\<E\> | [iterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractCollection.html#iterator())() Returns an iterator over the elements contained in this collection. |
| boolean | [remove](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractCollection.html#remove(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) o) Removes a single instance of the specified element from this collection, if it is present (optional operation). This implementation iterates over the collection looking for the specified element. |
| boolean | [removeAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractCollection.html#removeAll(java.util.Collection<?>))([Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<?\> c) Removes all of this collection's elements that are also contained in the specified collection (optional operation). This implementation iterates over this collection, checking each element returned by the iterator in turn to see if it's contained in the specified collection. |
| boolean | [retainAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractCollection.html#retainAll(java.util.Collection<?>))([Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<?\> c) Retains only the elements in this collection that are contained in the specified collection (optional operation). This implementation iterates over this collection, checking each element returned by the iterator in turn to see if it's contained in the specified collection. |
| abstract int | [size](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractCollection.html#size())() Returns the number of elements in this collection. |
| \<T\> T\[\] | [toArray](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractCollection.html#toArray(T[]))(T\[\] contents) Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array. This implementation returns an array containing all the elements returned by this collection's iterator in the same order, stored in consecutive elements of the array, starting with index `0`. |
| [Object\[\]](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) | [toArray](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractCollection.html#toArray())() Returns an array containing all of the elements in this collection. This implementation returns an array containing all the elements returned by this collection's iterator, in the same order, stored in consecutive elements of the array, starting with index `0`. |
| [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) | [toString](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractCollection.html#toString())() Returns a string representation of this collection. |

From class [java.lang.Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html)

|---|---|
| [Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) | [clone](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#clone())() Creates and returns a copy of this `Object`. |
| boolean | [equals](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#equals(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) obj) Compares this instance with the specified object and indicates if they are equal. |
| void | [finalize](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#finalize())() Invoked when the garbage collector has detected that this instance is no longer reachable. |
| final [Class](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html)\<?\> | [getClass](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#getClass())() Returns the unique instance of `https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html` that represents this object's class. |
| int | [hashCode](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#hashCode())() Returns an integer hash code for this object. |
| final void | [notify](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#notify())() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up. |
| final void | [notifyAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#notifyAll())() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up. |
| [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) | [toString](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#toString())() Returns a string containing a concise, human-readable description of this object. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait(long,%20int))(long timeout, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait(long))(long timeout) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait())() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object. |

From interface [java.util.Set](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html)

|---|---|
| abstract boolean | [add](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#add(E))(E e) Adds the specified element to this set if it is not already present (optional operation). |
| abstract boolean | [addAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#addAll(java.util.Collection<?%20extends%20E>))([Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<? 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 | [clear](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#clear())() Removes all of the elements from this set (optional operation). |
| abstract boolean | [contains](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#contains(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) o) Returns `true` if this set contains the specified element. |
| abstract boolean | [containsAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#containsAll(java.util.Collection<?>))([Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<?\> c) Returns `true` if this set contains all of the elements of the specified collection. |
| abstract boolean | [equals](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#equals(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) o) Compares the specified object with this set for equality. |
| abstract int | [hashCode](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#hashCode())() Returns the hash code value for this set. |
| abstract boolean | [isEmpty](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#isEmpty())() Returns `true` if this set contains no elements. |
| abstract [Iterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Iterator.html)\<E\> | [iterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#iterator())() Returns an iterator over the elements in this set. |
| abstract boolean | [remove](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#remove(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) o) Removes the specified element from this set if it is present (optional operation). |
| abstract boolean | [removeAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#removeAll(java.util.Collection<?>))([Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<?\> c) Removes from this set all of its elements that are contained in the specified collection (optional operation). |
| abstract boolean | [retainAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#retainAll(java.util.Collection<?>))([Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<?\> c) Retains only the elements in this set that are contained in the specified collection (optional operation). |
| abstract int | [size](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#size())() Returns the number of elements in this set (its cardinality). |
| [Spliterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html)\<E\> | [spliterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#spliterator())() Creates a `Spliterator` over the elements in this set. |
| abstract \<T\> T\[\] | [toArray](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#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. |
| abstract [Object\[\]](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) | [toArray](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html#toArray())() Returns an array containing all of the elements in this set. |

From interface [java.util.Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)

|---|---|
| abstract boolean | [add](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#add(E))(E e) Ensures that this collection contains the specified element (optional operation). |
| abstract boolean | [addAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#addAll(java.util.Collection<?%20extends%20E>))([Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<? extends E\> c) Adds all of the elements in the specified collection to this collection (optional operation). |
| abstract void | [clear](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#clear())() Removes all of the elements from this collection (optional operation). |
| abstract boolean | [contains](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#contains(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) o) Returns true if this collection contains the specified element. |
| abstract boolean | [containsAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#containsAll(java.util.Collection<?>))([Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<?\> c) Returns true if this collection contains all of the elements in the specified collection. |
| abstract boolean | [equals](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#equals(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) o) Compares the specified object with this collection for equality. |
| abstract int | [hashCode](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#hashCode())() Returns the hash code value for this collection. |
| abstract boolean | [isEmpty](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#isEmpty())() Returns true if this collection contains no elements. |
| abstract [Iterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Iterator.html)\<E\> | [iterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#iterator())() Returns an iterator over the elements in this collection. |
| [Stream](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/stream/Stream.html)\<E\> | [parallelStream](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#parallelStream())() Returns a possibly parallel `Stream` with this collection as its source. |
| abstract boolean | [remove](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#remove(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) o) Removes a single instance of the specified element from this collection, if it is present (optional operation). |
| abstract boolean | [removeAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#removeAll(java.util.Collection<?>))([Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<?\> c) Removes all of this collection's elements that are also contained in the specified collection (optional operation). |
| boolean | [removeIf](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#removeIf(java.util.function.Predicate<?%20super%20E>))([Predicate](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/function/Predicate.html)\<? super E\> filter) Removes all of the elements of this collection that satisfy the given predicate. |
| abstract boolean | [retainAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#retainAll(java.util.Collection<?>))([Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<?\> c) Retains only the elements in this collection that are contained in the specified collection (optional operation). |
| abstract int | [size](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#size())() Returns the number of elements in this collection. |
| [Spliterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html)\<E\> | [spliterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#spliterator())() Creates a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html` over the elements in this collection. |
| [Stream](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/stream/Stream.html)\<E\> | [stream](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#stream())() Returns a sequential `Stream` with this collection as its source. |
| abstract \<T\> T\[\] | [toArray](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#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 [Object\[\]](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) | [toArray](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html#toArray())() Returns an array containing all of the elements in this collection. |

From interface [java.lang.Iterable](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Iterable.html)

|---|---|
| void | [forEach](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Iterable.html#forEach(java.util.function.Consumer<?%20super%20T>))([Consumer](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/function/Consumer.html)\<? 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 [Iterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Iterator.html)\<E\> | [iterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Iterable.html#iterator())() Returns an iterator over elements of type `T`. |
| [Spliterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html)\<E\> | [spliterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Iterable.html#spliterator())() Creates a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html` over the elements described by this `Iterable`. |

## Public Constructors

#### public
**LinkedHashSet**
(int initialCapacity, float loadFactor)

Constructs a new, empty linked hash set with the specified initial
capacity and load factor.

##### Parameters

| initialCapacity | the initial capacity of the linked hash set |
| loadFactor | the load factor of the linked hash set |
|---|---|

##### Throws

| [IllegalArgumentException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IllegalArgumentException.html) | if the initial capacity is less than zero, or if the load factor is nonpositive |
|---|---|

#### public
**LinkedHashSet**
(int initialCapacity)

Constructs a new, empty linked hash set with the specified initial
capacity and the default load factor (0.75).

##### Parameters

| initialCapacity | the initial capacity of the LinkedHashSet |
|---|---|

##### Throws

| [IllegalArgumentException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IllegalArgumentException.html) | if the initial capacity is less than zero |
|---|---|

#### public
**LinkedHashSet**
()

Constructs a new, empty linked hash set with the default initial
capacity (16) and load factor (0.75).

#### public
**LinkedHashSet**
([Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<? extends E\> c)

Constructs a new linked hash set with the same elements as the
specified collection. The linked hash set is created with an initial
capacity sufficient to hold the elements in the specified collection
and the default load factor (0.75).

##### Parameters

| c | the collection whose elements are to be placed into this set |
|---|---|

##### Throws

| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified collection is null |
|---|---|

## Public Methods

#### public [Spliterator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html)\<E\>
**spliterator**
()

Creates a *[late-binding](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator#binding)*
and *fail-fast* `Spliterator` over the elements in this set.

The `Spliterator` reports `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html#SIZED`,
`https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html#DISTINCT`, and `ORDERED`. Implementations
should document the reporting of additional characteristic values.

##### Returns

- a `Spliterator` over the elements in this set