HashSet<E> class

An unordered hash-table based Set implementation.

An unordered hash-table based Set implementation.

The elements of a HashSet must have consistent equality and hashCode implementations. This means that the equals operation must define a stable equivalence relation on the elements (reflexive, symmetric, transitive, and consistent over time), and that the hashCode must consistent with equality, so that the same for objects that are considered equal.

The set allows null as an element.

Most simple operations on HashSet are done in (potentially amorteized) constant time: add, contains, remove, and length, provided the hash codes of objects are well distributed.

Implements
Implemented by

Constructors

HashSet({bool equals(E e1, E e2), int hashCode(E e), bool isValidKey(potentialKey)})
Create a hash set using the provided equals as equality.
HashSet.identity()
Creates an unordered identity-based set.
HashSet.from(Iterable elements)
Create a hash set containing all elements.

Instance Properties

iterator Iterator<E>
read-only
isEmpty bool Inherited
read-only
isNotEmpty bool Inherited
read-only
first E Inherited
read-only
last E Inherited
read-only
single E Inherited
read-only
length int Inherited
read-only

Instance Methods

remove(Object value) → bool Inherited
Removes value from the set. Returns true if value was in the set. Returns false otherwise. The method has no effect if value value was not in the set.
clear() → void Inherited
Removes all elements in the set.
take(int n) → Iterable<E> Inherited
Returns a lazy iterable of the count first elements of this iterable.
map(dynamic f(E element)) → Iterable Inherited
Returns a new lazy Iterable with elements that are created by calling f on each element of this Iterable in iteration order.
intersection(Set<Object> other) → Set<E> Inherited
Returns a new set which is the intersection between this set and other.
takeWhile(bool test(E value)) → Iterable<E> Inherited
Returns a lazy iterable of the leading elements satisfying 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
toSet() → Set<E> Inherited
Creates a [Set] containing the same elements as this iterable.
firstWhere(bool test(E element), {E orElse()}) → E Inherited
Returns the first element that satisfies the given predicate test.
forEach(void f(E element)) → void Inherited
Applies the function f to each element of this collection in iteration order.
difference(Set<E> other) → Set<E> Inherited
Returns a new set with the the elements of this that are not in other.
skipWhile(bool test(E value)) → Iterable<E> Inherited
Returns an Iterable that skips leading elements while test is satisfied.
join([String separator = ""]) → String Inherited
Converts each element to a String and concatenates the strings.
contains(Object value) → bool Inherited
Returns true if value is in the set.
union(Set<E> other) → Set<E> Inherited
Returns a new set which contains all the elements of this set and other.
removeAll(Iterable<Object> elements) → void Inherited
Removes each element of elements from this set.
add(E value) → bool Inherited
Adds value into the set. Returns true if value was added to the set.
lastWhere(bool test(E element), {E orElse()}) → E Inherited
Returns the last element that satisfies the given predicate test.
singleWhere(bool test(E element)) → E Inherited
Returns the single element that satisfies test.
addAll(Iterable<E> elements) → void Inherited
Adds all elements to this Set.
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.
containsAll(Iterable<Object> other) → bool Inherited
Returns whether this Set contains all the elements of other.
removeWhere(bool test(E element)) → void Inherited
Removes all elements of this set that satisfy test.
every(bool f(E element)) → bool Inherited
Checks whether every element of this iterable satisfies test.
any(bool f(E element)) → bool Inherited
Checks whether any element of this iterable satisfies test.
toList({bool growable: true}) → List<E> Inherited
Creates a List containing the elements of this Iterable.
where(bool f(E element)) → Iterable<E> Inherited
Returns a new lazy Iterable with all elements that satisfy the predicate test.
lookup(Object object) → E Inherited
If an object equal to object is in the set, return it.
skip(int n) → Iterable<E> Inherited
Returns an Iterable that provides all but the first count elements.
expand(Iterable f(E element)) → Iterable Inherited
Expands each element of this Iterableinto zero or more elements.
retainWhere(bool test(E element)) → void Inherited
Removes all elements of this set that fail to satisfy test.
retainAll(Iterable<Object> elements) → void Inherited
Removes all elements of this set that are not elements in elements.
elementAt(int index) → E Inherited
Returns the indexth element.