A collection of objects in which each object can occur only once.

That is, for each object of the element type, the object is either considered to be in the set, or to not be in the set.

Set implementations may consider some elements indistinguishable. These elements are treated as being the same for any operation on the set.

The default Set implementation, LinkedHashSet, considers objects indistinguishable if they are equal with regard to operator Object.==.

Iterating over elements of a set may be either unordered or ordered in some way. Examples:

  • A HashSet is unordered, which means that its iteration order is uspecified,

  • LinkedHashSet iterates in the insertion order of its elements, and
  • a sorted set like SplayTreeSet iterates the elements in sorted order.

It is generally not allowed to modify the set (add or remove elements) while an operation on the set is being performed, for example during a call to forEach or containsAll. Nor is it allowed to modify the set while iterating either the set itself or any Iterable that is backed by the set, such as the ones returned by methods like where and map.

Inheritance
Implements
  • EfficientLength
Implemented by

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 of this set.

last → E
read-only, inherited

length int
read-only, inherited

single → E
read-only, inherited

Constructors

Set()

Creates an empty Set.

Set.from(Iterable elements)

Creates a Set that contains all elements.

Set.identity()

Creates an empty identity Set.

Methods

add(E value) → bool

Adds value into the set. Returns true if value was added to the set.

addAll(Iterable<E> elements) → void

Adds all elements to this Set.

any(bool f(E element)) → bool
inherited

Checks whether any element of this iterable satisfies test.

clear() → void

Removes all elements in the set.

contains(Object value) → bool

Returns true if value is in the set.

containsAll(Iterable<Object> other) → bool

Returns whether this Set contains all the elements of other.

difference(Set<E> other) → Set<E>

Returns a new set with the the elements of this that are not in other.

elementAt(int index) → E
inherited

Returns the indexth 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 Iterableinto 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 f(E element)) → void
inherited

Applies the function f to each element of this collection in iteration order.

intersection(Set<Object> other) → Set<E>

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

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 calling f on each element of this Iterable 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

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.

removeAll(Iterable<Object> elements) → void

Removes each element of elements from this set.

removeWhere(bool test(E element)) → void

Removes all elements of this set that satisfy test.

retainAll(Iterable<Object> elements) → void

Removes all elements of this set that are not elements in elements.

retainWhere(bool test(E element)) → void

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 this Iterable.

toSet() → Set<E>

Creates a Set containing the same elements as this iterable.

toString() → String
inherited

Returns a string representation of (some of) the elements of this.

union(Set<E> other) → Set<E>

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 predicate test.