LinkedHashSet es una versión ordenada de HashSet que mantiene una lista doblemente vinculada en todos los elementos. Cuando se necesita mantener el orden de iteración, se utiliza esta clase. Al iterar a través de un HashSet, el orden es impredecible, mientras que un LinkedHashSet nos permite iterar a través de los elementos en el orden en que se insertaron. Al recorrer LinkedHashSet con un iterador, los elementos volverán al orden en que se insertaron.
Para implementar la API de LinkedHashSet primero, creamos una clase «LinkedHashSetImplmentation» y creamos todos los métodos de LinkedHashSet en esta clase.
Implementación de la API LinkedHashMap:
Java
// Java program to implement LinkedHashSet API
import java.util.*;
class LinkedHashSetImplementation<E> {
private LinkedHashSet<E> set;
// Constructor creates a new LinkedHashSet
public LinkedHashSetImplementation()
{
set = new LinkedHashSet<E>();
}
// Constructor creates a new empty linkedhash set
// according to the given set
public LinkedHashSetImplementation(
Collection<? extends E> set1)
{
set = new LinkedHashSet<E>(set1);
}
// Returns the size of the set
public int size() { return set.size(); }
// Returns true if set is empty otherwise return false
public boolean isEmpty() { return set.isEmpty(); }
// Returns true if set contains specified value
public boolean contains(Object val)
{
return set.contains(val);
}
// Returns an iterator over set elements
public Iterator<E> iterator() { return set.iterator(); }
// Returns an array containing all of the elements of
// the set
public Object[] toArray() { return set.toArray(); }
// Returns an array containing all of the elements of
// the set
public <T> T[] toArray(T[] a) { return set.toArray(a); }
// Add element to the set
public boolean add(E ele) { return set.add(ele); }
// Removes the specified element from the set if it is
// present
public boolean remove(Object ele)
{
return set.remove(ele);
}
// Returns true if the set contains all of the elements
// of the specified collection
public boolean containsAll(Collection<?> c)
{
return set.containsAll(c);
}
// Adds all of the elements in the specified collection
// to the set
public boolean addAll(Collection<? extends E> col)
{
return set.addAll(col);
}
// Retains only the elements in this set that are
// contained in the specified collection
public boolean retainAll(Collection<?> col)
{
return set.retainAll(col);
}
// Removes from this set all of its elements that are
// contained in the given collection
public boolean removeAll(Collection<?> col)
{
return set.retainAll(col);
}
// Removes all of the elements from the set
public void clear() { set.clear(); }
// Compares the specified object with the set
public boolean equals(Object obj)
{
return set.equals(obj);
}
// Returns the hash code value for the set
public int hashCode() { return set.hashCode(); }
}
public class GFG {
public static void main(String[] arg)
{
LinkedHashSetImplementation<Integer> set
= new LinkedHashSetImplementation<>();
// Add elements to set
set.add(10);
set.add(20);
set.add(30);
set.add(40);
set.add(50);
set.add(30);
set.add(40);
// Print the size of the set
System.out.println("Size of the LinkedHashset: "
+ set.size());
// Iterate set elements
System.out.println(
"The LinkedHashSet elements are:");
Iterator it = set.iterator();
while (it.hasNext()) {
// print set data
System.out.println(it.next());
}
// Check whether set is empty or not
System.out.println("The linkedHashSet is empty: "
+ set.isEmpty());
// Print true if set contains 60 else print false
System.out.println("LinkedHashSet contains 60: "
+ set.contains(60));
// Print true if set contains 40 else print false
System.out.println("LinkedHashSet contains 40: "
+ set.contains(40));
// Remove element from Set
set.remove(40);
// print size
System.out.println("Size of the linkedHashSet:"
+ set.size());
// Delete all the elements of the set
set.clear();
System.out.println("Size of the set after clear:"
+ set.size());
}
}
Producción
Size of the LinkedHashset: 5 The LinkedHashSet elements are: 10 20 30 40 50 The linkedHashSet is empty: false LinkedHashSet contains 60: false LinkedHashSet contains 40: true Size of the linkedHashSet:4 Size of the set after clear:0
Publicación traducida automáticamente
Artículo escrito por nikhilchhipa9 y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA