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
-
- Set<E>
- Implemented by
Constructors
- HashSet({bool equals(E e1, E e2), int hashCode(E e), bool isValidKey(potentialKey) })
-
Create a hash set using the provided
equalsas equality.factory - HashSet.from(Iterable elements)
-
Create a hash set containing all
elements.factory - HashSet.identity()
-
Creates an unordered identity-based set.
factory
Properties
- first → E
-
Returns the first element.
read-only, inherited - hashCode → int
-
Get a hash code for this object.
read-only, inherited - isEmpty → bool
-
Returns
trueif there are no elements in this collection.read-only, inherited - isNotEmpty → bool
-
Returns true if there is at least one element in this collection.
read-only, inherited - iterator → Iterator<E>
-
Provides an iterator that iterates over the elements of this set.
read-only - last → E
-
Returns the last element.
read-only, inherited - length → int
-
Returns the number of elements in
this.read-only, inherited - runtimeType → Type
-
A representation of the runtime type of the object.
read-only, inherited - single → E
-
Checks that this iterable has only one element, and returns that element.
read-only, inherited
Operators
-
operator ==(
other) → bool -
The equality operator.
inherited
Methods
-
add(
E value) → bool -
Adds
valueto the set.inherited -
addAll(
Iterable<E> elements) → void -
Adds all
elementsto this Set.inherited -
any(
bool f(E element)) → bool -
Checks whether any element of this iterable satisfies
test.inherited -
clear(
) → void -
Removes all elements in the set.
inherited -
contains(
Object value) → bool -
Returns true if
valueis in the set.inherited -
containsAll(
Iterable<Object> other) → bool -
Returns whether this Set contains all the elements of
other.inherited -
difference(
Set<E> other) → Set<E> -
Returns a new set with the elements of this that are not in
other.inherited -
elementAt(
int index) → E -
Returns the
indexth element.inherited -
every(
bool f(E element)) → bool -
Checks whether every element of this iterable satisfies
test.inherited -
expand(
Iterable f(E element)) → Iterable -
Expands each element of this Iterable into zero or more elements.
inherited -
firstWhere(
bool test(E element), { E orElse() }) → E -
Returns the first element that satisfies the given predicate
test.inherited -
fold(
initialValue, dynamic combine(previousValue, E element)) → dynamic -
Reduces a collection to a single value by iteratively combining each element of the collection with an existing value
inherited -
forEach(
void f(E element)) → void -
Applies the function
fto each element of this collection in iteration order.inherited -
intersection(
Set<Object> other) → Set<E> -
Returns a new set which is the intersection between this set and
other.inherited -
join(
[String separator = "" ]) → String -
Converts each element to a String and concatenates the strings.
inherited -
lastWhere(
bool test(E element), { E orElse() }) → E -
Returns the last element that satisfies the given predicate
test.inherited -
lookup(
Object object) → E -
If an object equal to
objectis in the set, return it.inherited -
map(
dynamic f(E e)) → Iterable -
Returns a new lazy Iterable with elements that are created by calling
fon each element of thisIterablein iteration order.inherited -
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent method or property is accessed.
inherited -
reduce(
E combine(E value, E element)) → E -
Reduces a collection to a single value by iteratively combining elements of the collection using the provided function.
inherited -
remove(
Object value) → bool -
Removes
valuefrom the set. Returns true ifvaluewas in the set. Returns false otherwise. The method has no effect ifvaluevalue was not in the set.inherited -
removeAll(
Iterable<Object> elements) → void -
Removes each element of
elementsfrom this set.inherited -
removeWhere(
bool test(E element)) → void -
Removes all elements of this set that satisfy
test.inherited -
retainAll(
Iterable<Object> elements) → void -
Removes all elements of this set that are not elements in
elements.inherited -
retainWhere(
bool test(E element)) → void -
Removes all elements of this set that fail to satisfy
test.inherited -
singleWhere(
bool test(E element)) → E -
Returns the single element that satisfies
test.inherited -
skip(
int count) → Iterable<E> -
Returns an Iterable that provides all but the first
countelements.inherited -
skipWhile(
bool test(E value)) → Iterable<E> -
Returns an
Iterablethat skips leading elements whiletestis satisfied.inherited -
take(
int count) → Iterable<E> -
Returns a lazy iterable of the
countfirst elements of this iterable.inherited -
takeWhile(
bool test(E value)) → Iterable<E> -
Returns a lazy iterable of the leading elements satisfying
test.inherited -
toList(
{bool growable: true }) → List<E> -
Creates a List containing the elements of this Iterable.
inherited -
toSet(
) → Set<E> -
Creates a
Setcontaining the same elements as this iterable.inherited -
toString(
) → String -
Returns a string representation of this object.
inherited -
union(
Set<E> other) → Set<E> -
Returns a new set which contains all the elements of this set and
other.inherited -
where(
bool test(E element)) → Iterable<E> -
Returns a new lazy Iterable with all elements that satisfy the predicate
test.inherited