Package java.util

Class LinkedHashSet<E>

java.lang.Object
java.util.AbstractCollection<E>
java.util.AbstractSet<E>
java.util.HashSet<E>
java.util.LinkedHashSet<E>
All Implemented Interfaces:
Serializable, Cloneable, Iterable<E>, Collection<E>, Set<E>
public class LinkedHashSet<E>
extends HashSet<E>
implements Set<E>, Cloneable, Serializable
LinkedHashSet is a variant of HashSet. Its entries are kept in a doubly-linked list. The iteration order is the order in which entries were inserted.

Null elements are allowed, and all the optional Set operations are supported.

Like HashSet, LinkedHashSet is not thread safe, so access by multiple threads must be synchronized by an external mechanism such as Collections.synchronizedSet(Set).

Since:
1.4
See Also:
Serialized Form

  • Constructor Details

    • LinkedHashSet

      public LinkedHashSet()
      Constructs a new empty instance of LinkedHashSet.

    • LinkedHashSet

      public LinkedHashSet​(int capacity)
      Constructs a new instance of LinkedHashSet with the specified capacity.
      Parameters:
      capacity - the initial capacity of this LinkedHashSet.

    • LinkedHashSet

      public LinkedHashSet​(int capacity, float loadFactor)
      Constructs a new instance of LinkedHashSet with the specified capacity and load factor.
      Parameters:
      capacity - the initial capacity.
      loadFactor - the initial load factor.

    • LinkedHashSet

      public LinkedHashSet​(Collection<? extends E> collection)
      Constructs a new instance of LinkedHashSet containing the unique elements in the specified collection.
      Parameters:
      collection - the collection of elements to add.