kotlin-stdlib / kotlin.collections / ArrayList

ArrayList

Common

1.0

class ArrayList<E> : MutableList<E>, RandomAccess

JVM

1.1

typealias ArrayList<E> = ArrayList<E>

1.1

open class ArrayList<E> : 
    AbstractMutableList<E>, 
    MutableList<E>, 
    RandomAccess

Native

1.3

class ArrayList<E> : 
    MutableList<E>, 
    RandomAccess, 
    AbstractMutableCollection<E>

Provides a MutableList implementation, which uses a resizable array as its backing storage.

This implementation doesn't provide a way to manage capacity, as backing JS array is resizeable itself. There is no speed advantage to pre-allocating array sizes in JavaScript, so this implementation does not include any of the capacity and "growth increment" concepts.

Constructors

<init>

Creates an empty ArrayList.

Common

Native

1.0

<init>()

Common

Native

1.0

<init>(initialCapacity: Int)

1.1

<init>(initialCapacity: Int = 0)

Creates an ArrayList filled from the elements collection.

Common

Native

1.0

<init>(elements: Collection<E>)

Properties

size

Common

Native

1.0

val size: Int

1.1

open val size: Int

Functions

add

Adds the specified element to the end of this list.

Common

Native

1.0

fun add(element: E): Boolean

1.1

open fun add(element: E): Boolean

Inserts an element into the list at the specified index.

Common

Native

1.0

fun add(index: Int, element: E)

1.1

open fun add(index: Int, element: E)

addAll

Adds all of the elements of the specified collection to the end of this list.

Common

Native

1.0

fun addAll(elements: Collection<E>): Boolean

1.1

open fun addAll(elements: Collection<E>): Boolean

Inserts all of the elements of the specified collection elements into this list at the specified index.

Common

Native

1.0

fun addAll(index: Int, elements: Collection<E>): Boolean

1.1

open fun addAll(index: Int, elements: Collection<E>): Boolean

clear

Removes all elements from this collection.

Common

Native

1.0

fun clear()

1.1

open fun clear()

Common

Native

1.0

contains

fun contains(element: E): Boolean

Common

Native

1.0

containsAll

fun containsAll(elements: Collection<E>): Boolean

Common

Native

1.0

ensureCapacity

Does nothing in this ArrayList implementation.

fun ensureCapacity(minCapacity: Int)

Native

1.3

equals

Indicates whether some other object is "equal to" this one. Implementations must fulfil the following requirements:

fun equals(other: Any?): Boolean

get

Returns the element at the specified index in the list.

Common

1.0

operator fun get(index: Int): E

1.1

open fun get(index: Int): E

Native

1.3

fun get(index: Int): E

Native

1.3

hashCode

Returns a hash code value for the object. The general contract of hashCode is:

fun hashCode(): Int

indexOf

Returns the index of the first occurrence of the specified element in the list, or -1 if the specified element is not contained in the list.

Common

Native

1.0

fun indexOf(element: E): Int

1.1

open fun indexOf(element: E): Int

Common

Native

1.0

isEmpty

fun isEmpty(): Boolean

Common

Native

1.0

iterator

fun iterator(): MutableIterator<E>

lastIndexOf

Returns the index of the last occurrence of the specified element in the list, or -1 if the specified element is not contained in the list.

Common

Native

1.0

fun lastIndexOf(element: E): Int

1.1

open fun lastIndexOf(element: E): Int

Common

Native

1.0

listIterator

Returns a list iterator over the elements in this list (in proper sequence).

fun listIterator(): MutableListIterator<E>

Returns a list iterator over the elements in this list (in proper sequence), starting at the specified index.

fun listIterator(index: Int): MutableListIterator<E>

remove

Removes a single instance of the specified element from this collection, if it is present.

Common

Native

1.0

fun remove(element: E): Boolean

1.1

open fun remove(element: E): Boolean

Common

Native

1.0

removeAll

Removes all of this collection's elements that are also contained in the specified collection.

fun removeAll(elements: Collection<E>): Boolean

removeAt

Removes an element at the specified index from the list.

Common

Native

1.0

fun removeAt(index: Int): E

1.1

open fun removeAt(index: Int): E

1.1

removeRange

Removes the range of elements from this list starting from fromIndex and ending with but not including toIndex.

open fun removeRange(fromIndex: Int, toIndex: Int)

Common

Native

1.0

retainAll

Retains only the elements in this collection that are contained in the specified collection.

fun retainAll(elements: Collection<E>): Boolean

set

Replaces the element at the specified position in this list with the specified element.

Common

Native

1.0

operator fun set(index: Int, element: E): E

1.1

open fun set(index: Int, element: E): E

Common

Native

1.0

subList

Returns a view of the portion of this list between the specified fromIndex (inclusive) and toIndex (exclusive). The returned list is backed by this list, so non-structural changes in the returned list are reflected in this list, and vice-versa.

fun subList(fromIndex: Int, toIndex: Int): MutableList<E>

1.1

toArray

open fun toArray(): Array<Any?>

toString

Returns a string representation of the object.

1.1

open fun toString(): String

Native

1.3

fun toString(): String

Common

Native

1.0

trimToSize

Does nothing in this ArrayList implementation.

fun trimToSize()

Inherited Functions

Common

1.0

containsAll

open fun containsAll(elements: Collection<E>): Boolean

Common

1.0

isEmpty

open fun isEmpty(): Boolean

Extension Properties

Common

JVM

Native

1.0

indices

Returns an IntRange of the valid indices for this collection.

val Collection<*>.indices: IntRange

Common

JVM

Native

1.0

lastIndex

Returns the index of the last item in the list or -1 if the list is empty.

val <T> List<T>.lastIndex: Int

Extension Functions

Common

JVM

Native

1.0

addAll

Adds all elements of the given elements collection to this MutableCollection.

fun <T> MutableCollection<in T>.addAll(
    elements: Iterable<T>
): Boolean

Adds all elements of the given elements sequence to this MutableCollection.

fun <T> MutableCollection<in T>.addAll(
    elements: Sequence<T>
): Boolean

Adds all elements of the given elements array to this MutableCollection.

fun <T> MutableCollection<in T>.addAll(
    elements: Array<out T>
): Boolean

Common

JVM

Native

1.0

all

Returns true if all elements match the given predicate.

fun <T> Iterable<T>.all(predicate: (T) -> Boolean): Boolean

Common

JVM

Native

1.0

any

Returns true if collection has at least one element.

fun <T> Iterable<T>.any(): Boolean

Returns true if at least one element matches the given predicate.

fun <T> Iterable<T>.any(predicate: (T) -> Boolean): Boolean

Common

JVM

Native

1.0

asIterable

Returns this collection as an Iterable.

fun <T> Iterable<T>.asIterable(): Iterable<T>

Common

JVM

Native

1.0

asSequence

Creates a Sequence instance that wraps the original collection returning its elements when being iterated.

fun <T> Iterable<T>.asSequence(): Sequence<T>

Common

JVM

Native

1.0

associate

Returns a Map containing key-value pairs provided by transform function applied to elements of the given collection.

fun <T, K, V> Iterable<T>.associate(
    transform: (T) -> Pair<K, V>
): Map<K, V>

Common

JVM

Native

1.0

associateBy

Returns a Map containing the elements from the given collection indexed by the key returned from keySelector function applied to each element.

fun <T, K> Iterable<T>.associateBy(
    keySelector: (T) -> K
): Map<K, T>

Returns a Map containing the values provided by valueTransform and indexed by keySelector functions applied to elements of the given collection.

fun <T, K, V> Iterable<T>.associateBy(
    keySelector: (T) -> K, 
    valueTransform: (T) -> V
): Map<K, V>

Common

JVM

Native

1.0

associateByTo

Populates and returns the destination mutable map with key-value pairs, where key is provided by the keySelector function applied to each element of the given collection and value is the element itself.

fun <T, K, M : MutableMap<in K, in T>> Iterable<T>.associateByTo(
    destination: M, 
    keySelector: (T) -> K
): M

Populates and returns the destination mutable map with key-value pairs, where key is provided by the keySelector function and and value is provided by the valueTransform function applied to elements of the given collection.

fun <T, K, V, M : MutableMap<in K, in V>> Iterable<T>.associateByTo(
    destination: M, 
    keySelector: (T) -> K, 
    valueTransform: (T) -> V
): M

Common

JVM

Native

1.0

associateTo

Populates and returns the destination mutable map with key-value pairs provided by transform function applied to each element of the given collection.

fun <T, K, V, M : MutableMap<in K, in V>> Iterable<T>.associateTo(
    destination: M, 
    transform: (T) -> Pair<K, V>
): M

Common

JVM

Native

1.3

associateWith

Returns a Map where keys are elements from the given collection and values are produced by the valueSelector function applied to each element.

fun <K, V> Iterable<K>.associateWith(
    valueSelector: (K) -> V
): Map<K, V>

Common

JVM

Native

1.3

associateWithTo

Populates and returns the destination mutable map with key-value pairs for each element of the given collection, where key is the element itself and value is provided by the valueSelector function applied to that key.

fun <K, V, M : MutableMap<in K, in V>> Iterable<K>.associateWithTo(
    destination: M, 
    valueSelector: (K) -> V
): M

Common

JVM

Native

1.0

binarySearch

Searches this list or its range for the provided element using the binary search algorithm. The list is expected to be sorted into ascending order according to the specified comparator, otherwise the result is undefined.

fun <T> List<T>.binarySearch(
    element: T, 
    comparator: Comparator<in T>, 
    fromIndex: Int = 0, 
    toIndex: Int = size
): Int

Searches this list or its range for an element for which the given comparison function returns zero using the binary search algorithm.

fun <T> List<T>.binarySearch(
    fromIndex: Int = 0, 
    toIndex: Int = size, 
    comparison: (T) -> Int
): Int

Common

JVM

Native

1.0

binarySearchBy

Searches this list or its range for an element having the key returned by the specified selector function equal to the provided key value using the binary search algorithm. The list is expected to be sorted into ascending order according to the Comparable natural ordering of keys of its elements. otherwise the result is undefined.

fun <T, K : Comparable<K>> List<T>.binarySearchBy(
    key: K?, 
    fromIndex: Int = 0, 
    toIndex: Int = size, 
    selector: (T) -> K?
): Int

Common

JVM

Native

1.2

chunked

Splits this collection into a list of lists each not exceeding the given size.

fun <T> Iterable<T>.chunked(size: Int): List<List<T>>

Splits this collection into several lists each not exceeding the given size and applies the given transform function to an each.

fun <T, R> Iterable<T>.chunked(
    size: Int, 
    transform: (List<T>) -> R
): List<R>

Common

JVM

Native

1.0

component1

Returns 1st element from the list.

operator fun <T> List<T>.component1(): T

Common

JVM

Native

1.0

component2

Returns 2nd element from the list.

operator fun <T> List<T>.component2(): T

Common

JVM

Native

1.0

component3

Returns 3rd element from the list.

operator fun <T> List<T>.component3(): T

Common

JVM

Native

1.0

component4

Returns 4th element from the list.

operator fun <T> List<T>.component4(): T

Common

JVM

Native

1.0

component5

Returns 5th element from the list.

operator fun <T> List<T>.component5(): T

Common

JVM

Native

1.0

contains

Returns true if element is found in the collection.

operator fun <T> Iterable<T>.contains(element: T): Boolean

Common

JVM

Native

1.0

containsAll

Checks if all elements in the specified collection are contained in this collection.

fun <T> Collection<T>.containsAll(
    elements: Collection<T>
): Boolean

Common

JVM

Native

1.0

count

Returns the number of elements matching the given predicate.

fun <T> Iterable<T>.count(predicate: (T) -> Boolean): Int

Common

JVM

Native

1.0

distinct

Returns a list containing only distinct elements from the given collection.

fun <T> Iterable<T>.distinct(): List<T>

Common

JVM

Native

1.0

distinctBy

Returns a list containing only elements from the given collection having distinct keys returned by the given selector function.

fun <T, K> Iterable<T>.distinctBy(
    selector: (T) -> K
): List<T>

Common

JVM

Native

1.0

drop

Returns a list containing all elements except first n elements.

fun <T> Iterable<T>.drop(n: Int): List<T>

Common

JVM

Native

1.0

dropLast

Returns a list containing all elements except last n elements.

fun <T> List<T>.dropLast(n: Int): List<T>

Common

JVM

Native

1.0

dropLastWhile

Returns a list containing all elements except last elements that satisfy the given predicate.

fun <T> List<T>.dropLastWhile(
    predicate: (T) -> Boolean
): List<T>

Common

JVM

Native

1.0

dropWhile

Returns a list containing all elements except first elements that satisfy the given predicate.

fun <T> Iterable<T>.dropWhile(
    predicate: (T) -> Boolean
): List<T>

Common

JVM

Native

1.0

elementAtOrElse

Returns an element at the given index or the result of calling the defaultValue function if the index is out of bounds of this collection.

fun <T> Iterable<T>.elementAtOrElse(
    index: Int, 
    defaultValue: (Int) -> T
): T

Returns an element at the given index or the result of calling the defaultValue function if the index is out of bounds of this list.

fun <T> List<T>.elementAtOrElse(
    index: Int, 
    defaultValue: (Int) -> T
): T

Common

JVM

Native

1.0

filter

Returns a list containing only elements matching the given predicate.

fun <T> Iterable<T>.filter(
    predicate: (T) -> Boolean
): List<T>

Common

JVM

Native

1.0

filterIndexed

Returns a list containing only elements matching the given predicate.

fun <T> Iterable<T>.filterIndexed(
    predicate: (index: Int, T) -> Boolean
): List<T>

Common

JVM

Native

1.0

filterIndexedTo

Appends all elements matching the given predicate to the given destination.

fun <T, C : MutableCollection<in T>> Iterable<T>.filterIndexedTo(
    destination: C, 
    predicate: (index: Int, T) -> Boolean
): C

Common

JVM

Native

1.0

filterIsInstance

Returns a list containing all elements that are instances of specified type parameter R.

fun <R> Iterable<*>.filterIsInstance(): List<R>

Common

JVM

Native

1.0

filterIsInstanceTo

Appends all elements that are instances of specified type parameter R to the given destination.

fun <R, C : MutableCollection<in R>> Iterable<*>.filterIsInstanceTo(
    destination: C
): C

Common

JVM

Native

1.0

filterNot

Returns a list containing all elements not matching the given predicate.

fun <T> Iterable<T>.filterNot(
    predicate: (T) -> Boolean
): List<T>

Common

JVM

Native

1.0

filterNotNull

Returns a list containing all elements that are not null.

fun <T : Any> Iterable<T?>.filterNotNull(): List<T>

Common

JVM

Native

1.0

filterNotNullTo

Appends all elements that are not null to the given destination.

fun <C : MutableCollection<in T>, T : Any> Iterable<T?>.filterNotNullTo(
    destination: C
): C

Common

JVM

Native

1.0

filterNotTo

Appends all elements not matching the given predicate to the given destination.

fun <T, C : MutableCollection<in T>> Iterable<T>.filterNotTo(
    destination: C, 
    predicate: (T) -> Boolean
): C

Common

JVM

Native

1.0

filterTo

Appends all elements matching the given predicate to the given destination.

fun <T, C : MutableCollection<in T>> Iterable<T>.filterTo(
    destination: C, 
    predicate: (T) -> Boolean
): C

Common

JVM

Native

1.0

find

Returns the first element matching the given predicate, or null if no such element was found.

fun <T> Iterable<T>.find(predicate: (T) -> Boolean): T?

Common

JVM

Native

1.0

findLast

Returns the last element matching the given predicate, or null if no such element was found.

fun <T> Iterable<T>.findLast(predicate: (T) -> Boolean): T?

fun <T> List<T>.findLast(predicate: (T) -> Boolean): T?

Common

JVM

Native

1.0

first

Returns the first element matching the given predicate.

fun <T> Iterable<T>.first(predicate: (T) -> Boolean): T

Common

JVM

Native

1.0

firstOrNull

Returns the first element matching the given predicate, or null if element was not found.

fun <T> Iterable<T>.firstOrNull(
    predicate: (T) -> Boolean
): T?

Common

JVM

Native

1.0

flatMap

Returns a single list of all elements yielded from results of transform function being invoked on each element of original collection.

fun <T, R> Iterable<T>.flatMap(
    transform: (T) -> Iterable<R>
): List<R>

Common

JVM

Native

1.0

flatMapTo

Appends all elements yielded from results of transform function being invoked on each element of original collection, to the given destination.

fun <T, R, C : MutableCollection<in R>> Iterable<T>.flatMapTo(
    destination: C, 
    transform: (T) -> Iterable<R>
): C

Common

JVM

Native

1.0

flatten

Returns a single list of all elements from all collections in the given collection.

fun <T> Iterable<Iterable<T>>.flatten(): List<T>

Common

JVM

Native

1.0

fold

Accumulates value starting with initial value and applying operation from left to right to current accumulator value and each element.

fun <T, R> Iterable<T>.fold(
    initial: R, 
    operation: (acc: R, T) -> R
): R

Common

JVM

Native

1.0

foldIndexed

Accumulates value starting with initial value and applying operation from left to right to current accumulator value and each element with its index in the original collection.

fun <T, R> Iterable<T>.foldIndexed(
    initial: R, 
    operation: (index: Int, acc: R, T) -> R
): R

Common

JVM

Native

1.0

foldRight

Accumulates value starting with initial value and applying operation from right to left to each element and current accumulator value.

fun <T, R> List<T>.foldRight(
    initial: R, 
    operation: (T, acc: R) -> R
): R

Common

JVM

Native

1.0

foldRightIndexed

Accumulates value starting with initial value and applying operation from right to left to each element with its index in the original list and current accumulator value.

fun <T, R> List<T>.foldRightIndexed(
    initial: R, 
    operation: (index: Int, T, acc: R) -> R
): R

Common

JVM

Native

1.0

forEach

Performs the given action on each element.

fun <T> Iterable<T>.forEach(action: (T) -> Unit)

Common

JVM

Native

1.0

forEachIndexed

Performs the given action on each element, providing sequential index with the element.

fun <T> Iterable<T>.forEachIndexed(
    action: (index: Int, T) -> Unit)

Common

JVM

Native

1.0

getOrElse

Returns an element at the given index or the result of calling the defaultValue function if the index is out of bounds of this list.

fun <T> List<T>.getOrElse(
    index: Int, 
    defaultValue: (Int) -> T
): T

Common

JVM

Native

1.0

getOrNull

Returns an element at the given index or null if the index is out of bounds of this list.

fun <T> List<T>.getOrNull(index: Int): T?

Common

JVM

Native

1.0

groupBy

Groups elements of the original collection by the key returned by the given keySelector function applied to each element and returns a map where each group key is associated with a list of corresponding elements.

fun <T, K> Iterable<T>.groupBy(
    keySelector: (T) -> K
): Map<K, List<T>>

Groups values returned by the valueTransform function applied to each element of the original collection by the key returned by the given keySelector function applied to the element and returns a map where each group key is associated with a list of corresponding values.

fun <T, K, V> Iterable<T>.groupBy(
    keySelector: (T) -> K, 
    valueTransform: (T) -> V
): Map<K, List<V>>

Common

JVM

Native

1.0

groupByTo

Groups elements of the original collection by the key returned by the given keySelector function applied to each element and puts to the destination map each group key associated with a list of corresponding elements.

fun <T, K, M : MutableMap<in K, MutableList<T>>> Iterable<T>.groupByTo(
    destination: M, 
    keySelector: (T) -> K
): M

Groups values returned by the valueTransform function applied to each element of the original collection by the key returned by the given keySelector function applied to the element and puts to the destination map each group key associated with a list of corresponding values.

fun <T, K, V, M : MutableMap<in K, MutableList<V>>> Iterable<T>.groupByTo(
    destination: M, 
    keySelector: (T) -> K, 
    valueTransform: (T) -> V
): M

Common

JVM

Native

1.1

groupingBy

Creates a Grouping source from a collection to be used later with one of group-and-fold operations using the specified keySelector function to extract a key from each element.

fun <T, K> Iterable<T>.groupingBy(
    keySelector: (T) -> K
): Grouping<T, K>

Common

JVM

Native

1.3

ifEmpty

Returns this array if it's not empty or the result of calling defaultValue function if the array is empty.

fun <C, R> C.ifEmpty(
    defaultValue: () -> R
): R where C : Array<*>, C : R

Common

JVM

Native

1.0

indexOf

Returns first index of element, or -1 if the collection does not contain element.

fun <T> Iterable<T>.indexOf(element: T): Int

Returns first index of element, or -1 if the list does not contain element.

fun <T> List<T>.indexOf(element: T): Int

Common

JVM

Native

1.0

indexOfFirst

Returns index of the first element matching the given predicate, or -1 if the collection does not contain such element.

fun <T> Iterable<T>.indexOfFirst(
    predicate: (T) -> Boolean
): Int

Returns index of the first element matching the given predicate, or -1 if the list does not contain such element.

fun <T> List<T>.indexOfFirst(predicate: (T) -> Boolean): Int

Common

JVM

Native

1.0

indexOfLast

Returns index of the last element matching the given predicate, or -1 if the collection does not contain such element.

fun <T> Iterable<T>.indexOfLast(
    predicate: (T) -> Boolean
): Int

Returns index of the last element matching the given predicate, or -1 if the list does not contain such element.

fun <T> List<T>.indexOfLast(predicate: (T) -> Boolean): Int

Common

JVM

Native

1.0

intersect

Returns a set containing all elements that are contained by both this collection and the specified collection.

infix fun <T> Iterable<T>.intersect(
    other: Iterable<T>
): Set<T>

Common

JVM

Native

1.0

isNotEmpty

Returns true if the collection is not empty.

fun <T> Collection<T>.isNotEmpty(): Boolean

Common

JVM

Native

1.3

isNullOrEmpty

Returns true if this nullable collection is either null or empty.

fun <T> Collection<T>?.isNullOrEmpty(): Boolean

Common

JVM

Native

1.0

joinTo

Appends the string from all the elements separated using separator and using the given prefix and postfix if supplied.

fun <T, A : Appendable> Iterable<T>.joinTo(
    buffer: A, 
    separator: CharSequence = ", ", 
    prefix: CharSequence = "", 
    postfix: CharSequence = "", 
    limit: Int = -1, 
    truncated: CharSequence = "...", 
    transform: ((T) -> CharSequence)? = null
): A

Common

JVM

Native

1.0

joinToString

Creates a string from all the elements separated using separator and using the given prefix and postfix if supplied.

fun <T> Iterable<T>.joinToString(
    separator: CharSequence = ", ", 
    prefix: CharSequence = "", 
    postfix: CharSequence = "", 
    limit: Int = -1, 
    truncated: CharSequence = "...", 
    transform: ((T) -> CharSequence)? = null
): String

Common

JVM

Native

1.0

last

Returns the last element matching the given predicate.

fun <T> Iterable<T>.last(predicate: (T) -> Boolean): T

fun <T> List<T>.last(predicate: (T) -> Boolean): T

Common

JVM

Native

1.0

lastIndexOf

Returns last index of element, or -1 if the collection does not contain element.

fun <T> Iterable<T>.lastIndexOf(element: T): Int

Returns last index of element, or -1 if the list does not contain element.

fun <T> List<T>.lastIndexOf(element: T): Int

Common

JVM

Native

1.0

lastOrNull

Returns the last element matching the given predicate, or null if no such element was found.

fun <T> Iterable<T>.lastOrNull(predicate: (T) -> Boolean): T?

fun <T> List<T>.lastOrNull(predicate: (T) -> Boolean): T?

Common

JVM

Native

1.0

map

Returns a list containing the results of applying the given transform function to each element in the original collection.

fun <T, R> Iterable<T>.map(transform: (T) -> R): List<R>

Common

JVM

Native

1.0

mapIndexed

Returns a list containing the results of applying the given transform function to each element and its index in the original collection.

fun <T, R> Iterable<T>.mapIndexed(
    transform: (index: Int, T) -> R
): List<R>

Common

JVM

Native

1.0

mapIndexedNotNull

Returns a list containing only the non-null results of applying the given transform function to each element and its index in the original collection.

fun <T, R : Any> Iterable<T>.mapIndexedNotNull(
    transform: (index: Int, T) -> R?
): List<R>

Common

JVM

Native

1.0

mapIndexedNotNullTo

Applies the given transform function to each element and its index in the original collection and appends only the non-null results to the given destination.

fun <T, R : Any, C : MutableCollection<in R>> Iterable<T>.mapIndexedNotNullTo(
    destination: C, 
    transform: (index: Int, T) -> R?
): C

Common

JVM

Native

1.0

mapIndexedTo

Applies the given transform function to each element and its index in the original collection and appends the results to the given destination.

fun <T, R, C : MutableCollection<in R>> Iterable<T>.mapIndexedTo(
    destination: C, 
    transform: (index: Int, T) -> R
): C

Common

JVM

Native

1.0

mapNotNull

Returns a list containing only the non-null results of applying the given transform function to each element in the original collection.

fun <T, R : Any> Iterable<T>.mapNotNull(
    transform: (T) -> R?
): List<R>

Common

JVM

Native

1.0

mapNotNullTo

Applies the given transform function to each element in the original collection and appends only the non-null results to the given destination.

fun <T, R : Any, C : MutableCollection<in R>> Iterable<T>.mapNotNullTo(
    destination: C, 
    transform: (T) -> R?
): C

Common

JVM

Native

1.0

mapTo

Applies the given transform function to each element of the original collection and appends the results to the given destination.

fun <T, R, C : MutableCollection<in R>> Iterable<T>.mapTo(
    destination: C, 
    transform: (T) -> R
): C

Common

JVM

Native

1.0

maxBy

Returns the first element yielding the largest value of the given function or null if there are no elements.

fun <T, R : Comparable<R>> Iterable<T>.maxBy(
    selector: (T) -> R
): T?

Common

JVM

Native

1.0

maxWith

Returns the first element having the largest value according to the provided comparator or null if there are no elements.

fun <T> Iterable<T>.maxWith(comparator: Comparator<in T>): T?

Common

JVM

Native

1.0

minBy

Returns the first element yielding the smallest value of the given function or null if there are no elements.

fun <T, R : Comparable<R>> Iterable<T>.minBy(
    selector: (T) -> R
): T?

Common

JVM

Native

1.0

minus

Returns a list containing all elements of the original collection without the first occurrence of the given element.

operator fun <T> Iterable<T>.minus(element: T): List<T>

Returns a list containing all elements of the original collection except the elements contained in the given elements array.

operator fun <T> Iterable<T>.minus(
    elements: Array<out T>
): List<T>

Returns a list containing all elements of the original collection except the elements contained in the given elements collection.

operator fun <T> Iterable<T>.minus(
    elements: Iterable<T>
): List<T>

Returns a list containing all elements of the original collection except the elements contained in the given elements sequence.

operator fun <T> Iterable<T>.minus(
    elements: Sequence<T>
): List<T>

Common

JVM

Native

1.0

minusAssign

Removes a single instance of the specified element from this mutable collection.

operator fun <T> MutableCollection<in T>.minusAssign(
    element: T)

Removes all elements contained in the given elements collection from this mutable collection.

operator fun <T> MutableCollection<in T>.minusAssign(
    elements: Iterable<T>)

Removes all elements contained in the given elements array from this mutable collection.

operator fun <T> MutableCollection<in T>.minusAssign(
    elements: Array<T>)

Removes all elements contained in the given elements sequence from this mutable collection.

operator fun <T> MutableCollection<in T>.minusAssign(
    elements: Sequence<T>)

Common

JVM

Native

1.0

minusElement

Returns a list containing all elements of the original collection without the first occurrence of the given element.

fun <T> Iterable<T>.minusElement(element: T): List<T>

Common

JVM

Native

1.0

minWith

Returns the first element having the smallest value according to the provided comparator or null if there are no elements.

fun <T> Iterable<T>.minWith(comparator: Comparator<in T>): T?

Common

JVM

Native

1.0

none

Returns true if the collection has no elements.

fun <T> Iterable<T>.none(): Boolean

Returns true if no elements match the given predicate.

fun <T> Iterable<T>.none(predicate: (T) -> Boolean): Boolean

Common

JVM

Native

1.1

onEach

Performs the given action on each element and returns the collection itself afterwards.

fun <T, C : Iterable<T>> C.onEach(action: (T) -> Unit): C

Common

JVM

Native

1.0

partition

Splits the original collection into pair of lists, where first list contains elements for which predicate yielded true, while second list contains elements for which predicate yielded false.

fun <T> Iterable<T>.partition(
    predicate: (T) -> Boolean
): Pair<List<T>, List<T>>

Common

JVM

Native

1.0

plus

Returns a list containing all elements of the original collection and then the given element.

operator fun <T> Iterable<T>.plus(element: T): List<T>

operator fun <T> Collection<T>.plus(element: T): List<T>

Returns a list containing all elements of the original collection and then all elements of the given elements array.

operator fun <T> Iterable<T>.plus(
    elements: Array<out T>
): List<T>

operator fun <T> Collection<T>.plus(
    elements: Array<out T>
): List<T>

Returns a list containing all elements of the original collection and then all elements of the given elements collection.

operator fun <T> Iterable<T>.plus(
    elements: Iterable<T>
): List<T>

operator fun <T> Collection<T>.plus(
    elements: Iterable<T>
): List<T>

Returns a list containing all elements of the original collection and then all elements of the given elements sequence.

operator fun <T> Iterable<T>.plus(
    elements: Sequence<T>
): List<T>

operator fun <T> Collection<T>.plus(
    elements: Sequence<T>
): List<T>

Common

JVM

Native

1.0

plusAssign

Adds the specified element to this mutable collection.

operator fun <T> MutableCollection<in T>.plusAssign(
    element: T)

Adds all elements of the given elements collection to this mutable collection.

operator fun <T> MutableCollection<in T>.plusAssign(
    elements: Iterable<T>)

Adds all elements of the given elements array to this mutable collection.

operator fun <T> MutableCollection<in T>.plusAssign(
    elements: Array<T>)

Adds all elements of the given elements sequence to this mutable collection.

operator fun <T> MutableCollection<in T>.plusAssign(
    elements: Sequence<T>)

Common

JVM

Native

1.0

plusElement

Returns a list containing all elements of the original collection and then the given element.

fun <T> Iterable<T>.plusElement(element: T): List<T>

fun <T> Collection<T>.plusElement(element: T): List<T>

Common

JVM

Native

1.3

random

Returns a random element from this collection.

fun <T> Collection<T>.random(): T

Returns a random element from this collection using the specified source of randomness.

fun <T> Collection<T>.random(random: Random): T

Common

JVM

Native

1.3

randomOrNull

Returns a random element from this collection, or null if this collection is empty.

fun <T> Collection<T>.randomOrNull(): T?

Returns a random element from this collection using the specified source of randomness, or null if this collection is empty.

fun <T> Collection<T>.randomOrNull(random: Random): T?

Common

JVM

Native

1.0

reduce

Accumulates value starting with the first element and applying operation from left to right to current accumulator value and each element.

fun <S, T : S> Iterable<T>.reduce(
    operation: (acc: S, T) -> S
): S

Common

JVM

Native

1.0

reduceIndexed

Accumulates value starting with the first element and applying operation from left to right to current accumulator value and each element with its index in the original collection.

fun <S, T : S> Iterable<T>.reduceIndexed(
    operation: (index: Int, acc: S, T) -> S
): S

Common

JVM

Native

1.3

reduceOrNull

Accumulates value starting with the first element and applying operation from left to right to current accumulator value and each element. Returns null if the collection is empty.

fun <S, T : S> Iterable<T>.reduceOrNull(
    operation: (acc: S, T) -> S
): S?

Common

JVM

Native

1.0

reduceRight

Accumulates value starting with last element and applying operation from right to left to each element and current accumulator value.

fun <S, T : S> List<T>.reduceRight(
    operation: (T, acc: S) -> S
): S

Common

JVM

Native

1.0

reduceRightIndexed

Accumulates value starting with last element and applying operation from right to left to each element with its index in the original list and current accumulator value.

fun <S, T : S> List<T>.reduceRightIndexed(
    operation: (index: Int, T, acc: S) -> S
): S

Common

JVM

Native

1.3

reduceRightOrNull

Accumulates value starting with last element and applying operation from right to left to each element and current accumulator value. Returns null if the list is empty.

fun <S, T : S> List<T>.reduceRightOrNull(
    operation: (T, acc: S) -> S
): S?

Common

JVM

Native

1.0

remove

Removes a single instance of the specified element from this collection, if it is present.

fun <T> MutableCollection<out T>.remove(element: T): Boolean

Removes the element at the specified index from this list. In Kotlin one should use the MutableList.removeAt function instead.

fun <T> MutableList<T>.remove(index: Int): T

Common

JVM

Native

1.0

removeAll

Removes all of this collection's elements that are also contained in the specified collection.

fun <T> MutableCollection<out T>.removeAll(
    elements: Collection<T>
): Boolean

Removes all elements from this MutableCollection that are also contained in the given elements collection.

fun <T> MutableCollection<in T>.removeAll(
    elements: Iterable<T>
): Boolean

Removes all elements from this MutableCollection that are also contained in the given elements sequence.

fun <T> MutableCollection<in T>.removeAll(
    elements: Sequence<T>
): Boolean

Removes all elements from this MutableCollection that are also contained in the given elements array.

fun <T> MutableCollection<in T>.removeAll(
    elements: Array<out T>
): Boolean

Removes all elements from this MutableIterable that match the given predicate.

fun <T> MutableIterable<T>.removeAll(
    predicate: (T) -> Boolean
): Boolean

Removes all elements from this MutableList that match the given predicate.

fun <T> MutableList<T>.removeAll(
    predicate: (T) -> Boolean
): Boolean

Common

JVM

Native

1.3

removeFirst

Removes the first element from this mutable list and returns that removed element, or throws NoSuchElementException if this list is empty.

fun <T> MutableList<T>.removeFirst(): T

Common

JVM

Native

1.3

removeFirstOrNull

Removes the first element from this mutable list and returns that removed element, or returns null if this list is empty.

fun <T> MutableList<T>.removeFirstOrNull(): T?

Common

JVM

Native

1.3

removeLast

Removes the last element from this mutable list and returns that removed element, or throws NoSuchElementException if this list is empty.

fun <T> MutableList<T>.removeLast(): T

Common

JVM

Native

1.3

removeLastOrNull

Removes the last element from this mutable list and returns that removed element, or returns null if this list is empty.

fun <T> MutableList<T>.removeLastOrNull(): T?

Native

1.3

replaceAll

Replaces each element in the list with a result of a transformation specified.

fun <T> MutableList<T>.replaceAll(transformation: (T) -> T)

Common

JVM

Native

1.0

retainAll

Retains only the elements in this collection that are contained in the specified collection.

fun <T> MutableCollection<out T>.retainAll(
    elements: Collection<T>
): Boolean

Retains only elements of this MutableCollection that are contained in the given elements collection.

fun <T> MutableCollection<in T>.retainAll(
    elements: Iterable<T>
): Boolean

Retains only elements of this MutableCollection that are contained in the given elements array.

fun <T> MutableCollection<in T>.retainAll(
    elements: Array<out T>
): Boolean

Retains only elements of this MutableCollection that are contained in the given elements sequence.

fun <T> MutableCollection<in T>.retainAll(
    elements: Sequence<T>
): Boolean

Retains only elements of this MutableIterable that match the given predicate.

fun <T> MutableIterable<T>.retainAll(
    predicate: (T) -> Boolean
): Boolean

Retains only elements of this MutableList that match the given predicate.

fun <T> MutableList<T>.retainAll(
    predicate: (T) -> Boolean
): Boolean

Common

JVM

Native

1.0

reversed

Returns a list with elements in reversed order.

fun <T> Iterable<T>.reversed(): List<T>

Common

JVM

Native

1.3

scan

Returns a list containing successive accumulation values generated by applying operation from left to right to each element and current accumulator value that starts with initial value.

fun <T, R> Iterable<T>.scan(
    initial: R, 
    operation: (acc: R, T) -> R
): List<R>

Common

JVM

Native

1.3

scanIndexed

Returns a list containing successive accumulation values generated by applying operation from left to right to each element, its index in the original collection and current accumulator value that starts with initial value.

fun <T, R> Iterable<T>.scanIndexed(
    initial: R, 
    operation: (index: Int, acc: R, T) -> R
): List<R>

Common

JVM

Native

1.3

scanReduce

Returns a list containing successive accumulation values generated by applying operation from left to right to each element and current accumulator value that starts with the first element of this collection.

fun <S, T : S> Iterable<T>.scanReduce(
    operation: (acc: S, T) -> S
): List<S>

Common

JVM

Native

1.3

scanReduceIndexed

fun <S, T : S> Iterable<T>.scanReduceIndexed(
    operation: (index: Int, acc: S, T) -> S
): List<S>

Common

JVM

Native

1.3

shuffle

Randomly shuffles elements in this mutable list using the specified random instance as the source of randomness.

fun <T> MutableList<T>.shuffle(random: Random)

Common

JVM

Native

1.3

shuffled

Returns a new list with the elements of this list randomly shuffled using the specified random instance as the source of randomness.

fun <T> Iterable<T>.shuffled(random: Random): List<T>

Common

JVM

Native

1.0

single

Returns the single element matching the given predicate, or throws exception if there is no or more than one matching element.

fun <T> Iterable<T>.single(predicate: (T) -> Boolean): T

Common

JVM

Native

1.0

singleOrNull

Returns the single element matching the given predicate, or null if element was not found or more than one element was found.

fun <T> Iterable<T>.singleOrNull(
    predicate: (T) -> Boolean
): T?

Common

JVM

Native

1.0

slice

Returns a list containing elements at indices in the specified indices range.

fun <T> List<T>.slice(indices: IntRange): List<T>

Returns a list containing elements at specified indices.

fun <T> List<T>.slice(indices: Iterable<Int>): List<T>

Common

JVM

Native

1.0

sortBy

Sorts elements in the list in-place according to natural sort order of the value returned by specified selector function.

fun <T, R : Comparable<R>> MutableList<T>.sortBy(
    selector: (T) -> R?)

Common

JVM

Native

1.0

sortByDescending

Sorts elements in the list in-place descending according to natural sort order of the value returned by specified selector function.

fun <T, R : Comparable<R>> MutableList<T>.sortByDescending(
    selector: (T) -> R?)

Common

JVM

Native

1.0

sortedBy

Returns a list of all elements sorted according to natural sort order of the value returned by specified selector function.

fun <T, R : Comparable<R>> Iterable<T>.sortedBy(
    selector: (T) -> R?
): List<T>

Common

JVM

Native

1.0

sortedByDescending

Returns a list of all elements sorted descending according to natural sort order of the value returned by specified selector function.

fun <T, R : Comparable<R>> Iterable<T>.sortedByDescending(
    selector: (T) -> R?
): List<T>

Common

JVM

Native

1.0

sortedWith

Returns a list of all elements sorted according to the specified comparator.

fun <T> Iterable<T>.sortedWith(
    comparator: Comparator<in T>
): List<T>

Common

JVM

Native

1.0

subtract

Returns a set containing all elements that are contained by this collection and not contained by the specified collection.

infix fun <T> Iterable<T>.subtract(
    other: Iterable<T>
): Set<T>

Common

JVM

Native

1.0

sumBy

Returns the sum of all values produced by selector function applied to each element in the collection.

fun <T> Iterable<T>.sumBy(selector: (T) -> Int): Int

Common

JVM

Native

1.0

sumByDouble

Returns the sum of all values produced by selector function applied to each element in the collection.

fun <T> Iterable<T>.sumByDouble(
    selector: (T) -> Double
): Double

Common

JVM

Native

1.0

take

Returns a list containing first n elements.

fun <T> Iterable<T>.take(n: Int): List<T>

Common

JVM

Native

1.0

takeLast

Returns a list containing last n elements.

fun <T> List<T>.takeLast(n: Int): List<T>

Common

JVM

Native

1.0

takeLastWhile

Returns a list containing last elements satisfying the given predicate.

fun <T> List<T>.takeLastWhile(
    predicate: (T) -> Boolean
): List<T>

Common

JVM

Native

1.0

takeWhile

Returns a list containing first elements satisfying the given predicate.

fun <T> Iterable<T>.takeWhile(
    predicate: (T) -> Boolean
): List<T>

Common

JVM

Native

1.0

toBooleanArray

Returns an array of Boolean containing all of the elements of this collection.

fun Collection<Boolean>.toBooleanArray(): BooleanArray

Common

JVM

Native

1.0

toByteArray

Returns an array of Byte containing all of the elements of this collection.

fun Collection<Byte>.toByteArray(): ByteArray

Common

JVM

Native

1.0

toCharArray

Returns an array of Char containing all of the elements of this collection.

fun Collection<Char>.toCharArray(): CharArray

Common

JVM

Native

1.0

toCollection

Appends all elements to the given destination collection.

fun <T, C : MutableCollection<in T>> Iterable<T>.toCollection(
    destination: C
): C

Native

1.3

toCStringArray

Convert this list of Kotlin strings to C array of C strings, allocating memory for the array and C strings with given AutofreeScope.

fun List<String>.toCStringArray(
    autofreeScope: AutofreeScope
): CPointer<CPointerVar<ByteVar>>

Native

1.3

toCValues

fun <T : CPointed> List<CPointer<T>?>.toCValues(): CValues<CPointerVar<T>>

Common

JVM

Native

1.0

toDoubleArray

Returns an array of Double containing all of the elements of this collection.

fun Collection<Double>.toDoubleArray(): DoubleArray

Common

JVM

Native

1.0

toFloatArray

Returns an array of Float containing all of the elements of this collection.

fun Collection<Float>.toFloatArray(): FloatArray

Common

JVM

Native

1.0

toHashSet

Returns a HashSet of all elements.

fun <T> Iterable<T>.toHashSet(): HashSet<T>

Common

JVM

Native

1.0

toIntArray

Returns an array of Int containing all of the elements of this collection.

fun Collection<Int>.toIntArray(): IntArray

Common

JVM

Native

1.0

toList

Returns a List containing all elements.

fun <T> Iterable<T>.toList(): List<T>

Common

JVM

Native

1.0

toLongArray

Returns an array of Long containing all of the elements of this collection.

fun Collection<Long>.toLongArray(): LongArray

Common

JVM

Native

1.0

toMap

Returns a new map containing all key-value pairs from the given collection of pairs.

fun <K, V> Iterable<Pair<K, V>>.toMap(): Map<K, V>

Populates and returns the destination mutable map with key-value pairs from the given collection of pairs.

fun <K, V, M : MutableMap<in K, in V>> Iterable<Pair<K, V>>.toMap(
    destination: M
): M

Common

JVM

Native

1.0

toMutableSet

Returns a mutable set containing all distinct elements from the given collection.

fun <T> Iterable<T>.toMutableSet(): MutableSet<T>

Common

JVM

Native

1.0

toSet

Returns a Set of all elements.

fun <T> Iterable<T>.toSet(): Set<T>

Common

JVM

Native

1.0

toShortArray

Returns an array of Short containing all of the elements of this collection.

fun Collection<Short>.toShortArray(): ShortArray

Common

JVM

Native

1.3

toUByteArray

Returns an array of UByte containing all of the elements of this collection.

fun Collection<UByte>.toUByteArray(): UByteArray

Common

JVM

Native

1.3

toUIntArray

Returns an array of UInt containing all of the elements of this collection.

fun Collection<UInt>.toUIntArray(): UIntArray

Common

JVM

Native

1.3

toULongArray

Returns an array of ULong containing all of the elements of this collection.

fun Collection<ULong>.toULongArray(): ULongArray

Common

JVM

Native

1.3

toUShortArray

Returns an array of UShort containing all of the elements of this collection.

fun Collection<UShort>.toUShortArray(): UShortArray

Common

JVM

Native

1.0

union

Returns a set containing all distinct elements from both collections.

infix fun <T> Iterable<T>.union(other: Iterable<T>): Set<T>

Common

JVM

Native

1.0

unzip

Returns a pair of lists, where first list is built from the first values of each pair from this collection, second list is built from the second values of each pair from this collection.

fun <T, R> Iterable<Pair<T, R>>.unzip(): Pair<List<T>, List<R>>

Native

1.3

waitForMultipleFutures

fun <T> Collection<Future<T>>.waitForMultipleFutures(
    millis: Int
): Set<Future<T>>

Common

JVM

Native

1.2

windowed

Returns a list of snapshots of the window of the given size sliding along this collection with the given step, where each snapshot is a list.

fun <T> Iterable<T>.windowed(
    size: Int, 
    step: Int = 1, 
    partialWindows: Boolean = false
): List<List<T>>

Returns a list of results of applying the given transform function to an each list representing a view over the window of the given size sliding along this collection with the given step.

fun <T, R> Iterable<T>.windowed(
    size: Int, 
    step: Int = 1, 
    partialWindows: Boolean = false, 
    transform: (List<T>) -> R
): List<R>

Common

JVM

Native

1.0

withIndex

Returns a lazy Iterable that wraps each element of the original collection into an IndexedValue containing the index of that element and the element itself.

fun <T> Iterable<T>.withIndex(): Iterable<IndexedValue<T>>

Common

JVM

Native

1.0

zip

Returns a list of pairs built from the elements of this collection and the other array with the same index. The returned list has length of the shortest collection.

infix fun <T, R> Iterable<T>.zip(
    other: Array<out R>
): List<Pair<T, R>>

Returns a list of values built from the elements of this collection and the other array with the same index using the provided transform function applied to each pair of elements. The returned list has length of the shortest collection.

fun <T, R, V> Iterable<T>.zip(
    other: Array<out R>, 
    transform: (a: T, b: R) -> V
): List<V>

Returns a list of pairs built from the elements of this collection and other collection with the same index. The returned list has length of the shortest collection.

infix fun <T, R> Iterable<T>.zip(
    other: Iterable<R>
): List<Pair<T, R>>

Returns a list of values built from the elements of this collection and the other collection with the same index using the provided transform function applied to each pair of elements. The returned list has length of the shortest collection.

fun <T, R, V> Iterable<T>.zip(
    other: Iterable<R>, 
    transform: (a: T, b: R) -> V
): List<V>

Common

JVM

Native

1.2

zipWithNext

Returns a list of pairs of each two adjacent elements in this collection.

fun <T> Iterable<T>.zipWithNext(): List<Pair<T, T>>

Returns a list containing the results of applying the given transform function to an each pair of two adjacent elements in this collection.

fun <T, R> Iterable<T>.zipWithNext(
    transform: (a: T, b: T) -> R
): List<R>