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. [...]
hashCode → int read-only, inherited: The hash code for this object. [...]
isEmpty → bool read-only, inherited: Returns true if there are no elements in this collection. [...]
isNotEmpty → bool read-only, inherited: Returns true if there is at least one element in this collection. [...]
iterator → Iterator<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. [...]
length → int read-only, inherited: Returns the number of elements in the iterable. [...]
runtimeType → Type 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