Java : LinkedHashSet with Examples
Last Modified : February 17, 2024 Published : June 28, 2022
LinkedHashSet (Java SE 18 & JDK 18) API Examples.
You will find code examples on most LinkedHashSet methods.
Summary
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.
final var set = new LinkedHashSet<String>();
set.add("a");
set.add("b");
set.add("c");
System.out.println(set); // [a, b, c]
System.out.println(set.size()); // 3
System.out.println(set.contains("a")); // true
System.out.println(set.contains("b")); // true
System.out.println(set.contains("X")); // false
final var linkedHashSet = new LinkedHashSet<String>();
linkedHashSet.add("xxx");
linkedHashSet.add("yyy");
linkedHashSet.add("aaa");
linkedHashSet.add("bbb");
System.out.println(linkedHashSet); // [xxx, yyy, aaa, bbb]
final var hashSet = new HashSet<String>();
hashSet.add("xxx");
hashSet.add("yyy");
hashSet.add("aaa");
hashSet.add("bbb");
System.out.println(hashSet); // [aaa, bbb, yyy, xxx]
Constructors
LinkedHashSet ()
Constructs a new, empty linked hash set with the default initial capacity (16) and load factor (0.75).
final var set = new LinkedHashSet<String>();
System.out.println(set); // []
System.out.println(set.isEmpty()); // true
set.add("a");
set.add("b");
set.add("c");
System.out.println(set); // [a, b, c]
System.out.println(set.size()); // 3
LinkedHashSet (int initialCapacity)
Constructs a new, empty linked hash set with the specified initial capacity and the default load factor (0.75).
final var set = new LinkedHashSet<String>(10000000);
System.out.println(set); // []
final var startTime = System.nanoTime();
for (int i = 0; i < 1000000; i++) {
set.add(String.valueOf(i));
}
final var endTime = System.nanoTime();
// 0.164871 sec.
System.out.printf("%f sec.%n", (endTime - startTime) / 1000000000.0);
final var set = new LinkedHashSet<String>(1);
System.out.println(set); // []
final var startTime = System.nanoTime();
for (int i = 0; i < 1000000; i++) {
set.add(String.valueOf(i));
}
final var endTime = System.nanoTime();
// 0.203662 sec.
System.out.printf("%f sec.%n", (endTime - startTime) / 1000000000.0);
LinkedHashSet (int initialCapacity, float loadFactor)
Constructs a new, empty linked hash set with the specified initial capacity and load factor.
final var set = new LinkedHashSet<String>(16, 0.05f);
System.out.println(set); // []
final var startTime = System.nanoTime();
for (int i = 0; i < 1000000; i++) {
set.add(String.valueOf(i));
}
final var endTime = System.nanoTime();
// 0.302754 sec.
System.out.printf("%f sec.%n", (endTime - startTime) / 1000000000.0);
final var set = new LinkedHashSet<String>(16, 0.75f);
System.out.println(set); // []
final var startTime = System.nanoTime();
for (int i = 0; i < 1000000; i++) {
set.add(String.valueOf(i));
}
final var endTime = System.nanoTime();
// 0.220326 sec.
System.out.printf("%f sec.%n", (endTime - startTime) / 1000000000.0);
LinkedHashSet (Collection<? extends E> c)
Constructs a new linked hash set with the same elements as the specified collection.
final var c = List.of("a", "b", "c");
final var set = new LinkedHashSet<>(c);
System.out.println(set); // [a, b, c]
System.out.println(set.size()); // 3
Methods
Spliterator<E> spliterator ()
Creates a late-binding and fail-fast Spliterator over the elements in this set.
final var set = new LinkedHashSet<String>();
Collections.addAll(set, "aaa", "bbb", "ccc");
System.out.println(set); // [aaa, bbb, ccc]
final var spliterator = set.spliterator();
spliterator.forEachRemaining(System.out::println);
// Result
// ↓
//aaa
//bbb
//ccc
Methods declared in HashSet
add, clear, clone, contains, isEmpty, iterator, remove, size, toArray, toArray
Please see the link below.
Methods declared in AbstractSet
Methods declared in AbstractCollection
addAll, containsAll, retainAll, toArray, toArray, toString
Please see the link below.
Methods declared in Collection
Methods declared in Iterable
Methods declared in Set
add, addAll, clear, contains, containsAll, equals, hashCode, isEmpty, iterator, remove, removeAll, retainAll, size, toArray, toArray
Please see the link below.
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