Queue<E> class

A Queue is a collection that can be manipulated at both ends. One can iterate over the elements of a queue through forEach or with an Iterator.

It is generally not allowed to modify the queue (add or remove entries) while an operation on the queue is being performed, for example during a call to forEach. Modifying the queue while it is being iterated will most likely break the iteration. This goes both for using the iterator directly, or for iterating an Iterable returned by a method like map or where.

Implementers

Constructors

Queue()
factory
Creates a queue.
Queue.from(Iterable elements)
factory
Creates a queue containing all elements. [...]
Queue.of(Iterable<E> elements)
factory
Creates a queue from elements. [...]

Properties

first → E
read-only, inherited
Returns the first element. [...]
hashCodeint
read-only, inherited
The hash code for this object. [...]
isEmptybool
read-only, inherited
Returns true if there are no elements in this collection. [...]
isNotEmptybool
read-only, inherited
Returns true if there is at least one element in this collection. [...]
iteratorIterator<E>
read-only, inherited
Returns a new Iterator that allows iterating the elements of this Iterable. [...]
last → E
read-only, inherited
Returns the last element. [...]
lengthint
read-only, inherited
Returns the number of elements in the iterable. [...]
runtimeTypeType
read-only, inherited
A representation of the runtime type of the object.
single → E
read-only, inherited
Checks that this iterable has only one element, and returns that element. [...]

Methods

add(E value) → void
Adds value at the end of the queue.
addAll(Iterable<E> iterable) → void
Adds all elements of iterable at the end of the queue. The length of the queue is extended by the length of iterable.
addFirst(E value) → void
Adds value at the beginning of the queue.
addLast(E value) → void
Adds value at the end of the queue.
any(bool test(E element)) → bool
inherited
Checks whether any element of this iterable satisfies test. [...]
cast<R>() → Queue<R>
override
Provides a view of this queue as a queue of R instances, if necessary. [...]
clear() → void
Removes all elements in the queue. The size of the queue becomes zero.
contains(Object? element) → bool
inherited
Whether the collection contains an element equal to element. [...]
elementAt(int index) → E
inherited
Returns the indexth element. [...]
every(bool test(E element)) → bool
inherited
Checks whether every element of this iterable satisfies test. [...]
expand<T>(Iterable<T> f(E element)) → Iterable<T>
inherited
Expands each element of this Iterable into zero or more elements. [...]
firstWhere(bool test(E element), {E orElse()}) → E
inherited
Returns the first element that satisfies the given predicate test. [...]
fold<T>(T initialValue, T combine(T previousValue, E element)) → T
inherited
Reduces a collection to a single value by iteratively combining each element of the collection with an existing value [...]
followedBy(Iterable<E> other) → Iterable<E>
inherited
Returns the lazy concatenation of this iterable and other. [...]
forEach(void f(E element)) → void
inherited
Applies the function f to each element of this collection in iteration order.
join([String separator = ""]) → String
inherited
Converts each element to a String and concatenates the strings. [...]
lastWhere(bool test(E element), {E orElse()}) → E
inherited
Returns the last element that satisfies the given predicate test. [...]
map<T>(T f(E e)) → Iterable<T>
inherited
Returns a new lazy Iterable with elements that are created by calling f on each element of this Iterable in iteration order. [...]
noSuchMethod(Invocation invocation) → dynamic
inherited
Invoked when a non-existent method or property is accessed. [...]
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
Remove a single instance of value from the queue. [...]
removeFirst() → E
Removes and returns the first element of this queue. [...]
removeLast() → E
Removes and returns the last element of the queue. [...]
removeWhere(bool test(E element)) → void
Removes all elements matched by test from the queue. [...]
retainWhere(bool test(E element)) → void
Removes all elements not matched by test from the queue. [...]
singleWhere(bool test(E element), {E orElse()}) → E
inherited
Returns the single element that satisfies test. [...]
skip(int count) → 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 count) → 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>
inherited
Creates a Set containing the same elements as this iterable. [...]
toString() → String
inherited
A string representation of this object. [...]
where(bool test(E element)) → Iterable<E>
inherited
Returns a new lazy Iterable with all elements that satisfy the predicate test. [...]
whereType<T>() → Iterable<T>
inherited
Returns a new lazy Iterable with all elements that have type T. [...]

Operators

operator ==(Object other) → bool
inherited
The equality operator. [...]

Static Methods

castFrom<S, T>(Queue<S> source) → Queue<T>
override
Adapts source to be a Queue<T>. [...]

© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dart.dev/stable/2.13.0/dart-collection/Queue-class.html