LinkedList<E> class

A custom implementation of a doubly linked list that implements the standard List<E> interface.

This LinkedList provides all list operations such as insertion, removal, iteration, indexing, and length tracking, but operates using linked nodes rather than a backing array.

⚠️ Note: While all List<E> methods are implemented, operations like random access, sort(), or shuffle() are inherently less efficient due to the sequential nature of linked lists compared to array-based lists.

πŸ“¦ Example Usage:

final list = LinkedList<String>();
list.add('A');
list.add('B');
list.insert(1, 'X');

print(list); // [A, X, B]
print(list.length); // 3
print(list[2]); // B

Internally, this list is backed by _Node<E> instances that link to their previous and next nodes. This allows efficient insertion and deletion at both ends and in the middle.

Implemented types
Available extensions
Annotations

Constructors

LinkedList()
Creates an empty linked list.

Properties

first ↔ E
The first element.
getter/setter pairoverride
firstOrNull β†’ T?

Available on Iterable<T>, provided by the IterableExtensions extension

The first element of this iterator, or null if the iterable is empty.
no setter
hashCode β†’ int
The hash code for this object.
no setterinherited
indexed β†’ Iterable<(int, T)>

Available on Iterable<T>, provided by the IterableExtensions extension

Pairs of elements of the indices and elements of this iterable.
no setter
isEmpty β†’ bool
Whether this collection has no elements.
no setteroverride
isNotEmpty β†’ bool
Whether this collection has at least one element.
no setteroverride
isOneAKind β†’ bool

Available on List<T>, provided by the ListExtensions extension

Checks if all list data have same value.
no setter
iterator β†’ Iterator<E>
A new Iterator that allows iterating the elements of this Iterable.
no setteroverride
last ↔ E
The last element.
getter/setter pairoverride
lastOrNull β†’ T?

Available on Iterable<T>, provided by the IterableExtensions extension

The last element of this iterable, or null if the iterable is empty.
no setter
length ↔ int
The number of objects in this list.
getter/setter pairoverride
nonNulls β†’ Iterable<T>

Available on Iterable<T?>, provided by the NullableIterableExtensions extension

The non-null elements of this iterable.
no setter
reversed β†’ Iterable<E>
An Iterable of the objects in this list in reverse order.
no setteroverride
runtimeType β†’ Type
A representation of the runtime type of the object.
no setterinherited
single β†’ E
Checks that this iterable has only one element, and returns that element.
no setteroverride
singleOrNull β†’ T?

Available on Iterable<T>, provided by the IterableExtensions extension

The single element of this iterator, or null.
no setter
toJS β†’ JSArray<T>

Available on List<T>, provided by the ListToJSArray extension

Converts this List to a JSArray by either casting, unwrapping, or cloning the List.
no setter
toJSProxyOrRef β†’ JSArray<T>

Available on List<T>, provided by the ListToJSArray extension

Converts this List to a JSArray by either casting, unwrapping, or proxying the List.
no setter
wait β†’ Future<List<T>>

Available on Iterable<Future<T>>, provided by the FutureIterable extension

Waits for futures in parallel.
no setter

Methods

add(E element) β†’ void
Adds value to the end of this list, extending the length by one.
override
addAll(Iterable<E> iterable) β†’ void
Appends all objects of iterable to the end of this list.
override
addAllIf(ConditionTester<T> condition, Iterable<T> items) β†’ void

Available on List<T>, provided by the ListExtensions extension

Adds all items from another list to a list if a condition is met.
addIf(ConditionTester<T> condition, T element) β†’ void

Available on List<T>, provided by the ListExtensions extension

Adds an item to a list if a condition is met.
all(ConditionTester<T> test) β†’ bool

Available on Iterable<T>, provided by the IterableExtension extension

Checks whether all elements of this iterable satisfy test.
any(bool test(E element)) β†’ bool
Checks whether any element of this iterable satisfies test.
override
asMap() β†’ Map<int, E>
An unmodifiable Map view of this list.
override
asNameMap() β†’ Map<String, T>

Available on Iterable<T>, provided by the EnumByName extension

Creates a map from the names of enum values to the values.
byName(String name) β†’ T

Available on Iterable<T>, provided by the EnumByName extension

Finds the enum value in this list with name name.
cast<R>() β†’ List<R>
Returns a view of this list as a list of R instances.
override
clear() β†’ void
Removes all objects from this list; the length of the list becomes zero.
override
contains(Object? element) β†’ bool
Whether the collection contains an element equal to element.
override
elementAt(int index) β†’ E
Returns the indexth element.
override
elementAtOrNull(int index) β†’ T?

Available on Iterable<T>, provided by the IterableExtensions extension

The element at position index of this iterable, or null.
every(bool test(E element)) β†’ bool
Checks whether every element of this iterable satisfies test.
override
expand<T>(Iterable<T> toElements(E element)) β†’ Iterable<T>
Expands each element of this Iterable into zero or more elements.
override
fillRange(int start, int end, [E? fillValue]) β†’ void
Overwrites a range of elements with fillValue.
override
filter(ConditionTester<T> test) β†’ Iterable<T>

Available on Iterable<T>, provided by the IterableExtension extension

Filters elements based on a predicate (alias for where).
filterWhere(ConditionTester<T> test) β†’ Iterable<T>

Available on Iterable<T>, provided by the IterableExtension extension

Filters elements based on a predicate.
find(ConditionTester<T> test) β†’ T?

Available on Iterable<T>, provided by the IterableExtension extension

Finds the first element that satisfies the given predicate.
findIndex(ConditionTester<T> test) β†’ int

Available on Iterable<T>, provided by the IterableExtension extension

Finds the index of the first element that satisfies the given predicate.
firstWhere(bool test(E element), {E orElse()?}) β†’ E
The first element that satisfies the given predicate test.
override
firstWhereOrNull(ConditionTester<T> test) β†’ T?

Available on Iterable<T>, provided by the IterableExtension extension

Returns the first element that satisfies the predicate or null if none match.
flatMap<E>(Iterable<E> selector(T item)) β†’ Iterable<E>

Available on Iterable<T>, provided by the IterableExtension extension

Flattens lists of items into a single iterable.
flatten<E>(E? selector(T item)) β†’ Iterable<E>

Available on Iterable<T>, provided by the IterableExtension extension

Transforms each element of the iterable into zero or more elements of type E and flattens the results.
flattenIterable<E>(Iterable<E>? selector(T item)) β†’ Iterable<E>

Available on Iterable<T>, provided by the IterableExtension extension

Transforms each element of the iterable into zero or more results of type E, and flattens the resulting collections into a single iterable.
fold<T>(T initialValue, T combine(T previousValue, E element)) β†’ T
Reduces a collection to a single value by iteratively combining each element of the collection with an existing value
override
followedBy(Iterable<E> other) β†’ Iterable<E>
Creates the lazy concatenation of this iterable and other.
override
forEach(void action(E element)) β†’ void
Invokes action on each element of this iterable in iteration order.
override
get([int index = 0]) β†’ T

Available on Iterable<T>, provided by the IterableExtension extension

Returns the element at the specified index.
getFirst() β†’ T

Available on Iterable<T>, provided by the IterableExtension extension

Returns the first element of the iterable.
getLast() β†’ T

Available on Iterable<T>, provided by the IterableExtension extension

Returns the last element of the iterable.
getRange(int start, int end) β†’ Iterable<E>
Creates an Iterable that iterates over a range of elements.
override
group<K>(K keySelector(T item)) β†’ Map<K, List<T>>

Available on Iterable<T>, provided by the IterableExtension extension

Groups the elements of the iterable by a key returned from the keySelector function.
groupBy<K>(K keySelector(T item)) β†’ Map<K, List<T>>

Available on Iterable<T>, provided by the IterableExtension extension

Groups elements of this iterable into a Map using the given keySelector.
groupByAndMap<K, V>(K keySelector(T item), V valueSelector(T item)) β†’ Map<K, List<V>>

Available on Iterable<T>, provided by the IterableExtension extension

Groups elements of this iterable into a Map using keySelector, and applies valueSelector to each element before storing it.
indexOf(Object? element, [int start = 0]) β†’ int
The first index of element in this list.
override
indexWhere(bool test(E element), [int start = 0]) β†’ int
The first index in the list that satisfies the provided test.
override
indexWhereOrNull(ConditionTester<T> test) β†’ int?

Available on Iterable<T>, provided by the IterableExtension extension

Finds the index of an element that satisfies the predicate or returns null if not found.
insert(int index, E element) β†’ void
Inserts element at position index in this list.
override
insertAll(int index, Iterable<E> iterable) β†’ void
Inserts all objects of iterable at position index in this list.
override
isLengthBetween(int min, int max) β†’ bool

Available on Iterable<T>, provided by the IterableExtension extension

Checks if length of double value is BETWEEN minLength to max.
isLengthEqualTo(int other) β†’ bool

Available on Iterable<T>, provided by the IterableExtension extension

Checks if length of double value is EQUAL to max.
isLengthEt(int max) β†’ bool

Available on Iterable<T>, provided by the IterableExtension extension

Short form for isLengthEqualTo
isLengthGreaterThan(int max) β†’ bool

Available on Iterable<T>, provided by the IterableExtension extension

Checks if length of double value is GREATER than max.
isLengthGreaterThanOrEqualTo(int max) β†’ bool

Available on Iterable<T>, provided by the IterableExtension extension

Checks if length of double value is GREATER OR EQUAL to max.
isLengthGt(int max) β†’ bool

Available on Iterable<T>, provided by the IterableExtension extension

Short form for isLengthGreaterThan
isLengthGtEt(int max) β†’ bool

Available on Iterable<T>, provided by the IterableExtension extension

Short form for isLengthGreaterThanOrEqualTo
isLengthLessThan(int max) β†’ bool

Available on Iterable<T>, provided by the IterableExtension extension

Checks if length of double value is LESS than max.
isLengthLessThanOrEqualTo(int max) β†’ bool

Available on Iterable<T>, provided by the IterableExtension extension

Checks if length of double value is LESS OR EQUAL to max.
isLengthLt(int max) β†’ bool

Available on Iterable<T>, provided by the IterableExtension extension

Short form for isLengthLessThan
isLengthLtEt(int max) β†’ bool

Available on Iterable<T>, provided by the IterableExtension extension

Short form for isLengthLessThanOrEqualTo
join([String separator = ""]) β†’ String
Converts each element to a String and concatenates the strings.
override
lastIndexOf(Object? element, [int? start]) β†’ int
The last index of element in this list.
override
lastIndexWhere(bool test(E element), [int? start]) β†’ int
The last index in the list that satisfies the provided test.
override
lastWhere(bool test(E element), {E orElse()?}) β†’ E
The last element that satisfies the given predicate test.
override
lastWhereOrNull(ConditionTester<T> test) β†’ T?

Available on Iterable<T>, provided by the IterableExtension extension

Returns the last element that satisfies the predicate or null if none match.
map<T>(T toElement(E e)) β†’ Iterable<T>
The current elements of this iterable modified by toElement.
override
none(ConditionTester<T> test) β†’ bool

Available on Iterable<T>, provided by the IterableExtension extension

Checks if no element matches the predicate.
noneMatch(ConditionTester<T> test) β†’ bool

Available on Iterable<T>, provided by the IterableExtension extension

Checks if none of the elements match a condition using noneMatch.
noSuchMethod(Invocation invocation) β†’ dynamic
Invoked when a nonexistent method or property is accessed.
inherited
pop() β†’ T?

Available on List<T>, provided by the ListExtensions extension

Removes and returns the last element of the list.
process(dynamic action(T item)) β†’ void

Available on Iterable<T>, provided by the IterableExtension extension

Processes each element of the iterable using the provided action function.
reduce(E combine(E value, E element)) β†’ E
Reduces a collection to a single value by iteratively combining elements of the collection using the provided function.
override
remove(Object? value) β†’ bool
Removes the first occurrence of value from this list.
override
removeAllIf(ConditionTester<T> condition, Iterable<T> items) β†’ void

Available on List<T>, provided by the ListExtensions extension

Removes all items from another list if a condition is met.
removeAt(int index) β†’ E
Removes the object at position index from this list.
override
removeIf(ConditionTester<T> condition, T element) β†’ void

Available on List<T>, provided by the ListExtensions extension

Removes an item from a list if a condition is met.
removeLast() β†’ E
Removes and returns the last object in this list.
override
removeRange(int start, int end) β†’ void
Removes a range of elements from the list.
override
removeWhere(bool test(E element)) β†’ void
Removes all objects from this list that satisfy test.
override
replaceRange(int start, int end, Iterable<E> newContents) β†’ void
Replaces a range of elements with the elements of replacements.
override
retainWhere(bool test(E element)) β†’ void
Removes all objects from this list that fail to satisfy test.
override
reverse() β†’ List<T>

Available on List<T>, provided by the ListExtensions extension

Returns a new list with the elements in reverse order.
setAll(int index, Iterable<E> iterable) β†’ void
Overwrites elements with the objects of iterable.
override
setRange(int start, int end, Iterable<E> iterable, [int skipCount = 0]) β†’ void
Writes some elements of iterable into a range of this list.
override
shift() β†’ T?

Available on List<T>, provided by the ListExtensions extension

Removes and returns the first element of the list.
shuffle([Random? random]) β†’ void
Shuffles the elements of this list randomly.
override
singleWhere(bool test(E element), {E orElse()?}) β†’ E
The single element that satisfies test.
override
skip(int count) β†’ Iterable<E>
Creates an Iterable that provides all but the first count elements.
override
skipWhile(bool test(E value)) β†’ Iterable<E>
Creates an Iterable that skips leading elements while test is satisfied.
override
sort([int compare(E a, E b)?]) β†’ void
Sorts this list according to the order specified by the compare function.
override
sortedByPublicFirst() β†’ List<T>

Available on Iterable<T>, provided by the SortByPublic extension

Sorts declarations with public visibility before private ones.
sortedByPublicFirstThenSyntheticLast() β†’ List<T>

Available on Iterable<T>, provided by the SortByPublic extension

Sorts declarations with public visibility first and synthetic declarations last.
stream() β†’ GenericStream<T>

Available on Iterable<T>, provided by the IterableExtension extension

Converts the iterable to a stream.
sublist(int start, [int? end]) β†’ List<E>
Returns a new list containing the elements between start and end.
override
take(int count) β†’ Iterable<E>
Creates a lazy iterable of the count first elements of this iterable.
override
takeWhile(bool test(E value)) β†’ Iterable<E>
Creates a lazy iterable of the leading elements satisfying test.
override
toList({bool growable = true}) β†’ List<E>
Creates a List containing the elements of this Iterable.
override
toMap<K, V>(K keySelector(T item), V valueSelector(T item)) β†’ Map<K, V>

Available on Iterable<T>, provided by the IterableExtension extension

Maps the iterable to a new iterable using the provided mapper function.
toSet() β†’ Set<E>
Creates a Set containing the same elements as this iterable.
override
toString() β†’ String
A string representation of this object.
override
where(bool test(E element)) β†’ Iterable<E>
Creates a new lazy Iterable with all elements that satisfy the predicate test.
override
whereOrNull(ConditionTester<T> test) β†’ Iterable<T>?

Available on Iterable<T>, provided by the IterableExtension extension

Returns an iterable with elements that match a condition, or null if none match.
whereType<T>() β†’ Iterable<T>
Creates a new lazy Iterable with all elements that have type T.
override
whereType<U>() β†’ Iterable<T>

Available on Iterable<T>, provided by the IterableExtension extension

Filters elements of a specific type T.

Operators

operator +(List<E> other) β†’ List<E>
Returns the concatenation of this list and other.
override
operator ==(Object other) β†’ bool
The equality operator.
inherited
operator [](int index) β†’ E
The object at the given index in the list.
override
operator []=(int index, E value) β†’ void
Sets the value at the given index in the list to value.
override