# ListQueue<E> class final

List based Queue.

Keeps a cyclic buffer of elements, and grows to a larger buffer when it fills up. This guarantees constant time peek and remove operations, and amortized constant time add operations.

The structure is efficient for any queue or stack usage.

Example:

``````final queue = ListQueue<int>();
``````

``````queue.add(5);
print(queue); // {0, 5, 10, 1, 2, 3}
``````

To check if the queue is empty, use isEmpty or isNotEmpty. To find the number of queue entries, use length.

``````final isEmpty = queue.isEmpty; // false
final queueSize = queue.length; // 6
``````

To get first or last item from queue, use first or last.

``````final first = queue.first; // 0
final last = queue.last; // 3
``````

To get item value using index, use elementAt.

``````final itemAt = queue.elementAt(2); // 10
``````

To convert queue to list, call toList.

``````final numbers = queue.toList();
print(numbers); // [0, 5, 10, 1, 2, 3]
``````

To remove item from queue, call remove, removeFirst or removeLast.

``````queue.remove(10);
queue.removeFirst();
queue.removeLast();
print(queue); // {5, 1, 2}
``````

To remove multiple elements at the same time, use removeWhere.

``````queue.removeWhere((element) => element == 1);
print(queue); // {5, 2}
``````

To remove all elements in this queue that do not meet a condition, use retainWhere.

``````queue.retainWhere((element) => element < 4);
print(queue); // {2}
``````

To remove all items and empty the set, use clear.

``````queue.clear();
print(queue.isEmpty); // true
print(queue); // {}
``````
Inheritance
Implemented types
Available Extensions

## Constructors

ListQueue([int? initialCapacity])
Create an empty queue.
ListQueue.from(Iterable elements)
Create a `ListQueue` containing all `elements`.
factory
ListQueue.of(Iterable<E> elements)
Create a `ListQueue` from `elements`.
factory

## Properties

first → E
The first element.
hashCode int
The hash code for this object.
isEmpty bool
Whether this collection has no elements.
isNotEmpty bool
Whether this collection has at least one element.
iterator Iterator<E>
A new `Iterator` that allows iterating the elements of this `Iterable`.
last → E
The last element.
length int
Returns the number of elements in the iterable.
runtimeType Type
A representation of the runtime type of the object.
single → E
Checks that this iterable has only one element, and returns that element.

## Methods

Adds `value` at the end of the queue.
override
Adds all elements of `iterable` at the end of the queue. The length of the queue is extended by the length of `iterable`.
override
Adds `value` at the beginning of the queue.
override
Adds `value` at the end of the queue.
override
any(bool test(E element)) bool
Checks whether any element of this iterable satisfies `test`.
inherited
cast<R>() Queue<R>
A view of this iterable as an iterable of `R` instances.
override
Removes all elements in the queue. The size of the queue becomes zero.
override
contains( element) bool
Whether the collection contains an element equal to `element`.
inherited
elementAt(int index) → E
Returns the `index`th element.
every(bool test(E element)) bool
Checks whether every element of this iterable satisfies `test`.
inherited
expand<T>(Iterable<T> toElements(E element)) Iterable<T>
Expands each element of this Iterable into zero or more elements.
inherited
firstWhere(bool test(E element), {E orElse()?}) → E
The first element that satisfies the given predicate `test`.
inherited
fold<T>(T initialValue, T combine(T previousValue, E element)) → T
Reduces a collection to a single value by iteratively combining each element of the collection with an existing value
inherited
followedBy(Iterable<E> other) Iterable<E>
Creates the lazy concatenation of this iterable and `other`.
inherited
forEach(void f(E element)) → void
Invokes `action` on each element of this iterable in iteration order.
join([String separator = ""])
Converts each element to a String and concatenates the strings.
inherited
lastWhere(bool test(E element), {E orElse()?}) → E
The last element that satisfies the given predicate `test`.
inherited
map<T>(T toElement(E element)) Iterable<T>
The current elements of this iterable modified by `toElement`.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent 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( value) bool
Removes a single instance of `value` from the queue.
override
removeFirst() → E
Removes and returns the first element of this queue.
override
removeLast() → E
Removes and returns the last element of the queue.
override
removeWhere(bool test(E element)) → void
Remove all elements matched by `test`.
override
retainWhere(bool test(E element)) → void
Remove all elements not matched by `test`.
override
singleWhere(bool test(E element), {E orElse()?}) → E
The single element that satisfies `test`.
inherited
skip(int count) Iterable<E>
Creates an Iterable that provides all but the first `count` elements.
inherited
skipWhile(bool test(E element)) Iterable<E>
Creates an `Iterable` that skips leading elements while `test` is satisfied.
inherited
take(int count) Iterable<E>
Creates a lazy iterable of the `count` first elements of this iterable.
inherited
takeWhile(bool test(E element)) Iterable<E>
Creates 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.
toSet() Set<E>
Creates a Set containing the same elements as this iterable.
inherited
toString()
Returns a string representation of (some of) the elements of `this`.
override
where(bool test(E element)) Iterable<E>
Creates a new lazy Iterable with all elements that satisfy the predicate `test`.
inherited
whereType<T>() Iterable<T>
Creates a new lazy Iterable with all elements that have type `T`.
inherited

## Operators

operator ==(Object other) bool
The equality operator.
inherited