A LinkedHashSet is a hash-table based Set implementation.
The LinkedHashSet
also keep track of the order that elements were inserted
in, and iteration happens in first-to-last insertion order.
The elements of a LinkedHashSet
must have consistent Object.operator==
and Object.hashCode implementations. This means that the ==
operator
must define a stable equivalence relation on the elements (reflexive,
symmetric, transitive, and consistent over time), and that hashCode
must be the same for objects that are considered equal by ==
.
The set allows null
as an element.
Iteration of elements is done in element insertion order. An element that was added after another will occur later in the iteration. Adding an element that is already in the set does not change its position in the iteration order, but removing an element and adding it again, will make it the last element of an iteration.
Most simple operations on HashSet
are done in (potentially amortized)
constant time: add, contains, remove, and length
, provided the hash
codes of objects are well distributed..
- Implements
-
- HashSet<E>
Properties
- first → E
-
read-only, inherited
- isEmpty → bool
-
read-only, inherited
- isNotEmpty → bool
-
read-only, inherited
- iterator → Iterator<E>
-
read-only
Provides an iterator that iterates over the elements in insertion order.
- last → E
-
read-only, inherited
- length → int
-
read-only, inherited
- single → E
-
read-only, inherited
Constructors
- LinkedHashSet({bool equals(E e1, E e2), int hashCode(E e), bool isValidKey(potentialKey)})
-
Create an insertion-ordered hash set using the provided
equals
andhashCode
.… - LinkedHashSet.from(Iterable<E> elements)
-
Create a linked hash set containing all
elements
.… - LinkedHashSet.identity()
-
Creates an insertion-ordered identity-based set.…
Methods
-
add(
E value) → bool -
inherited
Adds
value
into the set. Returnstrue
ifvalue
was added to the set.… -
addAll(
Iterable<E> elements) → void -
inherited
Adds all
elements
to this Set.… -
any(
bool f(E element)) → bool -
inherited
Checks whether any element of this iterable satisfies
test
.… -
clear(
) → void -
inherited
Removes all elements in the set.
-
contains(
Object value) → bool -
inherited
Returns true if
value
is in the set. -
containsAll(
Iterable<Object> other) → bool -
inherited
Returns whether this Set contains all the elements of
other
. -
difference(
Set<E> other) → Set<E> -
inherited
Returns a new set with the the elements of this that are not in
other
.… -
elementAt(
int index) → E -
inherited
Returns the
index
th element.… -
every(
bool f(E element)) → bool -
inherited
Checks whether every element of this iterable satisfies
test
.… -
expand(
Iterable f(E element)) → Iterable -
inherited
Expands each element of this
Iterable
into zero or more elements.… -
firstWhere(
bool test(E value), {E orElse()}) → E -
inherited
Returns the first element that satisfies the given predicate
test
.… -
fold(
initialValue, dynamic combine(previousValue, E element)) → dynamic -
inherited
Reduces a collection to a single value by iteratively combining each element of the collection with an existing value…
-
forEach(
void action(E element)) → void -
Executes a function on each element of the set.…
-
intersection(
Set<Object> other) → Set<E> -
inherited
Returns a new set which is the intersection between this set and
other
.… -
join(
[String separator = ""]) → String -
inherited
Converts each element to a
String
and concatenates the strings.… -
lastWhere(
bool test(E value), {E orElse()}) → E -
inherited
Returns the last element that satisfies the given predicate
test
.… -
lookup(
Object object) → E -
inherited
If an object equal to
object
is in the set, return it.… -
map(
dynamic f(E element)) → Iterable -
inherited
Returns a new lazy
Iterable
with elements that are created by callingf
on each element of thisIterable
in iteration order.… -
reduce(
E combine(E value, E element)) → E -
inherited
Reduces a collection to a single value by iteratively combining elements of the collection using the provided function.…
-
remove(
Object value) → bool -
inherited
Removes
value
from the set. Returns true ifvalue
was in the set. Returns false otherwise. The method has no effect ifvalue
value was not in the set. -
removeAll(
Iterable<Object> elements) → void -
inherited
Removes each element of
elements
from this set. -
removeWhere(
bool test(E element)) → void -
inherited
Removes all elements of this set that satisfy
test
. -
retainAll(
Iterable<Object> elements) → void -
inherited
Removes all elements of this set that are not elements in
elements
.… -
retainWhere(
bool test(E element)) → void -
inherited
Removes all elements of this set that fail to satisfy
test
. -
singleWhere(
bool test(E value)) → E -
inherited
Returns the single element that satisfies
test
.… -
skip(
int n) → Iterable<E> -
inherited
Returns an Iterable that provides all but the first
count
elements.… -
skipWhile(
bool test(E value)) → Iterable<E> -
inherited
Returns an Iterable that skips leading elements while
test
is satisfied.… -
take(
int n) → Iterable<E> -
inherited
Returns a lazy iterable of the
count
first elements of this iterable.… -
takeWhile(
bool test(E value)) → Iterable<E> -
inherited
Returns a lazy iterable of the leading elements satisfying
test
.… -
toList(
{bool growable: true}) → List<E> -
inherited
Creates a
List
containing the elements of thisIterable
.… -
toSet(
) → Set<E> -
inherited
Creates a
Set
containing the same elements as this iterable.… -
union(
Set<E> other) → Set<E> -
inherited
Returns a new set which contains all the elements of this set and
other
.… -
where(
bool f(E element)) → Iterable<E> -
inherited
Returns a new lazy
Iterable
with all elements that satisfy the predicatetest
.…