kotlin-stdlib / kotlin.collections / AbstractMap

AbstractMap

Common
JVM
JS
Native
1.1
abstract class AbstractMap<K, out V> : Map<K, V>

Provides a skeletal implementation of the read-only Map interface.

The implementor is required to implement entries property, which should return read-only set of map entries.

Parameters

K - the type of map keys. The map is invariant on its key type.

V - the type of map values. The map is covariant on its value type.

Constructors

Common
JVM
JS
Native
1.0

<init>

Provides a skeletal implementation of the read-only Map interface.

AbstractMap()

Properties

Common
JVM
JS
Native
1.0

keys

Returns a read-only Set of all keys in this map.

open val keys: Set<K>
Common
JVM
JS
Native
1.0

size

open val size: Int
Common
JVM
JS
Native
1.0

values

Returns a read-only Collection of all values in this map.

open val values: Collection<V>

Functions

Common
JVM
JS
Native
1.0

containsKey

open fun containsKey(key: K): Boolean
Common
JVM
JS
Native
1.0

containsValue

open fun containsValue(value: V): Boolean
Common
JVM
JS
Native
1.0

equals

Compares this map with other instance with the ordered structural equality.

open fun equals(other: Any?): Boolean
Common
JVM
JS
Native
1.0

get

open operator fun get(key: K): V?
Common
JVM
JS
Native
1.0

hashCode

Returns the hash code value for this map.

open fun hashCode(): Int
Common
JVM
JS
Native
1.0

isEmpty

open fun isEmpty(): Boolean
Common
JVM
JS
Native
1.0

toString

Returns a string representation of the object.

open fun toString(): String

Extension Functions

Common
JVM
JS
Native
1.0

all

Returns true if all entries match the given predicate.

fun <K, V> Map<out K, V>.all(
    predicate: (Entry<K, V>) -> Boolean
): Boolean
Common
JVM
JS
Native
1.0

any

Returns true if map has at least one entry.

fun <K, V> Map<out K, V>.any(): Boolean

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

fun <K, V> Map<out K, V>.any(
    predicate: (Entry<K, V>) -> Boolean
): Boolean
Common
JVM
JS
Native
1.0

asIterable

Creates an Iterable instance that wraps the original map returning its entries when being iterated.

fun <K, V> Map<out K, V>.asIterable(): Iterable<Entry<K, V>>
Common
JVM
JS
Native
1.0

asSequence

Creates a Sequence instance that wraps the original map returning its entries when being iterated.

fun <K, V> Map<out K, V>.asSequence(): Sequence<Entry<K, V>>
Common
JVM
JS
Native
1.0

contains

Checks if the map contains the given key.

operator fun <K, V> Map<out K, V>.contains(key: K): Boolean
Common
JVM
JS
Native
1.0

containsKey

Returns true if the map contains the specified key.

fun <K> Map<out K, *>.containsKey(key: K): Boolean
Common
JVM
JS
Native
1.0

containsValue

Returns true if the map maps one or more keys to the specified value.

fun <K, V> Map<K, V>.containsValue(value: V): Boolean
Common
JVM
JS
Native
1.0

count

Returns the number of entries in this map.

fun <K, V> Map<out K, V>.count(): Int

Returns the number of entries matching the given predicate.

fun <K, V> Map<out K, V>.count(
    predicate: (Entry<K, V>) -> Boolean
): Int
Common
JVM
JS
Native
1.0

filter

Returns a new map containing all key-value pairs matching the given predicate.

fun <K, V> Map<out K, V>.filter(
    predicate: (Entry<K, V>) -> Boolean
): Map<K, V>
Common
JVM
JS
Native
1.0

filterKeys

Returns a map containing all key-value pairs with keys matching the given predicate.

fun <K, V> Map<out K, V>.filterKeys(
    predicate: (K) -> Boolean
): Map<K, V>
Common
JVM
JS
Native
1.0

filterNot

Returns a new map containing all key-value pairs not matching the given predicate.

fun <K, V> Map<out K, V>.filterNot(
    predicate: (Entry<K, V>) -> Boolean
): Map<K, V>
Common
JVM
JS
Native
1.0

filterNotTo

Appends all entries not matching the given predicate into the given destination.

fun <K, V, M : MutableMap<in K, in V>> Map<out K, V>.filterNotTo(
    destination: M,
    predicate: (Entry<K, V>) -> Boolean
): M
Common
JVM
JS
Native
1.0

filterTo

Appends all entries matching the given predicate into the mutable map given as destination parameter.

fun <K, V, M : MutableMap<in K, in V>> Map<out K, V>.filterTo(
    destination: M,
    predicate: (Entry<K, V>) -> Boolean
): M
Common
JVM
JS
Native
1.0

filterValues

Returns a map containing all key-value pairs with values matching the given predicate.

fun <K, V> Map<out K, V>.filterValues(
    predicate: (V) -> Boolean
): Map<K, V>
Common
JVM
JS
Native
1.0

flatMap

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

fun <K, V, R> Map<out K, V>.flatMap(
    transform: (Entry<K, V>) -> Iterable<R>
): List<R>
Common
JVM
JS
Native
1.0

flatMapTo

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

fun <K, V, R, C : MutableCollection<in R>> Map<out K, V>.flatMapTo(
    destination: C,
    transform: (Entry<K, V>) -> Iterable<R>
): C
Common
JVM
JS
Native
1.0

forEach

Performs the given action on each entry.

fun <K, V> Map<out K, V>.forEach(
    action: (Entry<K, V>) -> Unit)
Common
JVM
JS
Native
1.0

get

Returns the value corresponding to the given key, or null if such a key is not present in the map.

operator fun <K, V> Map<out K, V>.get(key: K): V?
Common
JVM
JS
Native
1.0

getOrElse

Returns the value for the given key, or the result of the defaultValue function if there was no entry for the given key.

fun <K, V> Map<K, V>.getOrElse(
    key: K,
    defaultValue: () -> V
): V
Common
JVM
JS
Native
1.0

getValue

Returns the value of the property for the given object from this read-only map.

operator fun <V, V1 : V> Map<in String, V>.getValue(
    thisRef: Any?,
    property: KProperty<*>
): V1

Returns the value for the given key or throws an exception if there is no such key in the map.

fun <K, V> Map<K, V>.getValue(key: K): V
Common
JVM
JS
Native
1.3

ifEmpty

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

fun <M, R> M.ifEmpty(
    defaultValue: () -> R
): R where M : Map<*, *>, M : R
Common
JVM
JS
Native
1.0

isNotEmpty

Returns true if this map is not empty.

fun <K, V> Map<out K, V>.isNotEmpty(): Boolean
Common
JVM
JS
Native
1.3

isNullOrEmpty

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

fun <K, V> Map<out K, V>?.isNullOrEmpty(): Boolean
Common
JVM
JS
Native
1.0

iterator

Returns an Iterator over the entries in the Map.

operator fun <K, V> Map<out K, V>.iterator(): Iterator<Entry<K, V>>
Common
JVM
JS
Native
1.0

map

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

fun <K, V, R> Map<out K, V>.map(
    transform: (Entry<K, V>) -> R
): List<R>
Common
JVM
JS
Native
1.0

mapKeys

Returns a new Map with entries having the keys obtained by applying the transform function to each entry in this Map and the values of this map.

fun <K, V, R> Map<out K, V>.mapKeys(
    transform: (Entry<K, V>) -> R
): Map<R, V>
Common
JVM
JS
Native
1.0

mapKeysTo

Populates the given destination map with entries having the keys obtained by applying the transform function to each entry in this Map and the values of this map.

fun <K, V, R, M : MutableMap<in R, in V>> Map<out K, V>.mapKeysTo(
    destination: M,
    transform: (Entry<K, V>) -> R
): M
Common
JVM
JS
Native
1.0

mapNotNull

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

fun <K, V, R : Any> Map<out K, V>.mapNotNull(
    transform: (Entry<K, V>) -> R?
): List<R>
Common
JVM
JS
Native
1.0

mapNotNullTo

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

fun <K, V, R : Any, C : MutableCollection<in R>> Map<out K, V>.mapNotNullTo(
    destination: C,
    transform: (Entry<K, V>) -> R?
): C
Common
JVM
JS
Native
1.0

mapTo

Applies the given transform function to each entry of the original map and appends the results to the given destination.

fun <K, V, R, C : MutableCollection<in R>> Map<out K, V>.mapTo(
    destination: C,
    transform: (Entry<K, V>) -> R
): C
Common
JVM
JS
Native
1.0

mapValues

Returns a new map with entries having the keys of this map and the values obtained by applying the transform function to each entry in this Map.

fun <K, V, R> Map<out K, V>.mapValues(
    transform: (Entry<K, V>) -> R
): Map<K, R>
Common
JVM
JS
Native
1.0

mapValuesTo

Populates the given destination map with entries having the keys of this map and the values obtained by applying the transform function to each entry in this Map.

fun <K, V, R, M : MutableMap<in K, in R>> Map<out K, V>.mapValuesTo(
    destination: M,
    transform: (Entry<K, V>) -> R
): M
Common
JVM
JS
Native
1.0

maxBy

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

fun <K, V, R : Comparable<R>> Map<out K, V>.maxBy(
    selector: (Entry<K, V>) -> R
): Entry<K, V>?
Common
JVM
JS
Native
1.0

maxWith

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

fun <K, V> Map<out K, V>.maxWith(
    comparator: Comparator<in Entry<K, V>>
): Entry<K, V>?
Common
JVM
JS
Native
1.0

minBy

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

fun <K, V, R : Comparable<R>> Map<out K, V>.minBy(
    selector: (Entry<K, V>) -> R
): Entry<K, V>?
Common
JVM
JS
Native
1.1

minus

Returns a map containing all entries of the original map except the entry with the given key.

operator fun <K, V> Map<out K, V>.minus(key: K): Map<K, V>

Returns a map containing all entries of the original map except those entries the keys of which are contained in the given keys collection.

operator fun <K, V> Map<out K, V>.minus(
    keys: Iterable<K>
): Map<K, V>

Returns a map containing all entries of the original map except those entries the keys of which are contained in the given keys array.

operator fun <K, V> Map<out K, V>.minus(
    keys: Array<out K>
): Map<K, V>

Returns a map containing all entries of the original map except those entries the keys of which are contained in the given keys sequence.

operator fun <K, V> Map<out K, V>.minus(
    keys: Sequence<K>
): Map<K, V>
Common
JVM
JS
Native
1.0

minWith

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

fun <K, V> Map<out K, V>.minWith(
    comparator: Comparator<in Entry<K, V>>
): Entry<K, V>?
Common
JVM
JS
Native
1.0

none

Returns true if the map has no entries.

fun <K, V> Map<out K, V>.none(): Boolean

Returns true if no entries match the given predicate.

fun <K, V> Map<out K, V>.none(
    predicate: (Entry<K, V>) -> Boolean
): Boolean
Common
JVM
JS
Native
1.1

onEach

Performs the given action on each entry and returns the map itself afterwards.

fun <K, V, M : Map<out K, V>> M.onEach(
    action: (Entry<K, V>) -> Unit
): M
Common
JVM
JS
Native
1.0

orEmpty

Returns the Map if its not null, or the empty Map otherwise.

fun <K, V> Map<K, V>?.orEmpty(): Map<K, V>
Common
JVM
JS
Native
1.0

plus

Creates a new read-only map by replacing or adding an entry to this map from a given key-value pair.

operator fun <K, V> Map<out K, V>.plus(
    pair: Pair<K, V>
): Map<K, V>

Creates a new read-only map by replacing or adding entries to this map from a given collection of key-value pairs.

operator fun <K, V> Map<out K, V>.plus(
    pairs: Iterable<Pair<K, V>>
): Map<K, V>

Creates a new read-only map by replacing or adding entries to this map from a given array of key-value pairs.

operator fun <K, V> Map<out K, V>.plus(
    pairs: Array<out Pair<K, V>>
): Map<K, V>

Creates a new read-only map by replacing or adding entries to this map from a given sequence of key-value pairs.

operator fun <K, V> Map<out K, V>.plus(
    pairs: Sequence<Pair<K, V>>
): Map<K, V>

Creates a new read-only map by replacing or adding entries to this map from another map.

operator fun <K, V> Map<out K, V>.plus(
    map: Map<out K, V>
): Map<K, V>
Common
JVM
JS
Native
1.0

toList

Returns a List containing all key-value pairs.

fun <K, V> Map<out K, V>.toList(): List<Pair<K, V>>
Common
JVM
JS
Native
1.1

toMap

Returns a new read-only map containing all key-value pairs from the original map.

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

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

fun <K, V, M : MutableMap<in K, in V>> Map<out K, V>.toMap(
    destination: M
): M
Common
JVM
JS
Native
1.1

toMutableMap

Returns a new mutable map containing all key-value pairs from the original map.

fun <K, V> Map<out K, V>.toMutableMap(): MutableMap<K, V>
Common
JVM
JS
Native
1.0

withDefault

Returns a wrapper of this read-only map, having the implicit default value provided with the specified function defaultValue.

fun <K, V> Map<K, V>.withDefault(
    defaultValue: (key: K) -> V
): Map<K, V>

Inheritors

AbstractMutableMap

Provides a skeletal implementation of the MutableMap interface.

Common
1.3
abstract class AbstractMutableMap<K, V> : MutableMap<K, V>
JVM
1.1
abstract class AbstractMutableMap<K, V> : 
    MutableMap<K, V>,
    AbstractMap<K, V>
JS
Native
1.1
abstract class AbstractMutableMap<K, V> : 
    AbstractMap<K, V>,
    MutableMap<K, V>