kotlin-stdlib / kotlin.collections / LinkedHashMap

LinkedHashMap

Common
1.0
class LinkedHashMap<K, V> : MutableMap<K, V>
(source)
JVM
1.1
typealias LinkedHashMap<K, V> = LinkedHashMap<K, V>
(source)
JS
1.1
open class LinkedHashMap<K, V> : 
    HashMap<K, V>,
    MutableMap<K, V>
(source)
Native
1.3
typealias LinkedHashMap<K, V> = HashMap<K, V>
(source)

Hash table based implementation of the MutableMap interface, which additionally preserves the insertion order of entries during the iteration.

The insertion order is preserved by the corresponding InternalMap implementation.

Constructors

Common
JS
1.0

<init>

Creates a new empty LinkedHashMap.

<init>()

Creates a new empty LinkedHashMap with the specified initial capacity.

<init>(initialCapacity: Int)

Creates a new empty LinkedHashMap with the specified initial capacity and load factor.

<init>(initialCapacity: Int, loadFactor: Float)

Creates a new LinkedHashMap filled with the contents of the specified original map.

<init>(original: Map<out K, V>)

Properties

Common
1.0

entries

val entries: MutableSet<MutableEntry<K, V>>
Common
1.0

keys

val keys: MutableSet<K>
Common
1.0

size

val size: Int
Common
1.0

values

val values: MutableCollection<V>

Functions

Common
1.0

clear

fun clear()
Common
1.0

containsKey

fun containsKey(key: K): Boolean
Common
1.0

containsValue

fun containsValue(value: V): Boolean
Common
1.0

get

fun get(key: K): V?
Common
1.0

isEmpty

fun isEmpty(): Boolean
Common
1.0

put

fun put(key: K, value: V): V?
Common
1.0

putAll

fun putAll(from: Map<out K, V>)
Common
1.0

remove

fun remove(key: K): V?

Inherited Functions

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
Native
1.3

hashCode

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

fun hashCode(): Int
Native
1.3

toString

Returns a string representation of the object.

fun toString(): String

Extension Functions

Common
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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
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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
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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
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Native
1.0

containsKey

Returns true if the map contains the specified key.

fun <K> Map<out K, *>.containsKey(key: K): Boolean
Common
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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
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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
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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
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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
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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
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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
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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
1.5

firstNotNullOf

Returns the first non-null value produced by transform function being applied to entries of this map in iteration order, or throws NoSuchElementException if no non-null value was produced.

fun <K, V, R : Any> Map<out K, V>.firstNotNullOf(
    transform: (Entry<K, V>) -> R?
): R
Common
JVM
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Native
1.5

firstNotNullOfOrNull

Returns the first non-null value produced by transform function being applied to entries of this map in iteration order, or null if no non-null value was produced.

fun <K, V, R : Any> Map<out K, V>.firstNotNullOfOrNull(
    transform: (Entry<K, V>) -> R?
): R?
Common
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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>
fun <K, V, R> Map<out K, V>.flatMap(
    transform: (Entry<K, V>) -> Sequence<R>
): List<R>
Common
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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
fun <K, V, R, C : MutableCollection<in R>> Map<out K, V>.flatMapTo(
    destination: C,
    transform: (Entry<K, V>) -> Sequence<R>
): C
Common
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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
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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
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Native
1.0

getOrElse

Returns the value for the given key if the value is present and not null. Otherwise, returns the result of the defaultValue function.

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

getOrPut

Returns the value for the given key if the value is present and not null. Otherwise, calls the defaultValue function, puts its result into the map under the given key and returns the call result.

fun <K, V> MutableMap<K, V>.getOrPut(
    key: K,
    defaultValue: () -> V
): V
Common
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Native
1.1

getValue

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
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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
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Native
1.0

isNotEmpty

Returns true if this map is not empty.

fun <K, V> Map<out K, V>.isNotEmpty(): Boolean
Common
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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
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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
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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
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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
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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
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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
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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
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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
1.4

maxByOrNull

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>.maxByOrNull(
    selector: (Entry<K, V>) -> R
): Entry<K, V>?
Common
JVM
JS
Native
1.4

maxOf

Returns the largest value among all values produced by selector function applied to each entry in the map.

fun <K, V> Map<out K, V>.maxOf(
    selector: (Entry<K, V>) -> Double
): Double
fun <K, V> Map<out K, V>.maxOf(
    selector: (Entry<K, V>) -> Float
): Float
fun <K, V, R : Comparable<R>> Map<out K, V>.maxOf(
    selector: (Entry<K, V>) -> R
): R
Common
JVM
JS
Native
1.4

maxOfOrNull

Returns the largest value among all values produced by selector function applied to each entry in the map or null if there are no entries.

fun <K, V> Map<out K, V>.maxOfOrNull(
    selector: (Entry<K, V>) -> Double
): Double?
fun <K, V> Map<out K, V>.maxOfOrNull(
    selector: (Entry<K, V>) -> Float
): Float?
fun <K, V, R : Comparable<R>> Map<out K, V>.maxOfOrNull(
    selector: (Entry<K, V>) -> R
): R?
Common
JVM
JS
Native
1.4

maxOfWith

Returns the largest value according to the provided comparator among all values produced by selector function applied to each entry in the map.

fun <K, V, R> Map<out K, V>.maxOfWith(
    comparator: Comparator<in R>,
    selector: (Entry<K, V>) -> R
): R
Common
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Native
1.4

maxOfWithOrNull

Returns the largest value according to the provided comparator among all values produced by selector function applied to each entry in the map or null if there are no entries.

fun <K, V, R> Map<out K, V>.maxOfWithOrNull(
    comparator: Comparator<in R>,
    selector: (Entry<K, V>) -> R
): R?
Common
JVM
JS
Native
1.7

maxWith

Returns the first entry having the largest value according to the provided comparator.

fun <K, V> Map<out K, V>.maxWith(
    comparator: Comparator<in Entry<K, V>>
): Entry<K, V>
Common
JVM
JS
Native
1.4

maxWithOrNull

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>.maxWithOrNull(
    comparator: Comparator<in Entry<K, V>>
): Entry<K, V>?
Common
JVM
JS
Native
1.4

minByOrNull

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>.minByOrNull(
    selector: (Entry<K, V>) -> R
): Entry<K, V>?
Common
JVM
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Native
1.4

minOf

Returns the smallest value among all values produced by selector function applied to each entry in the map.

fun <K, V> Map<out K, V>.minOf(
    selector: (Entry<K, V>) -> Double
): Double
fun <K, V> Map<out K, V>.minOf(
    selector: (Entry<K, V>) -> Float
): Float
fun <K, V, R : Comparable<R>> Map<out K, V>.minOf(
    selector: (Entry<K, V>) -> R
): R
Common
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Native
1.4

minOfOrNull

Returns the smallest value among all values produced by selector function applied to each entry in the map or null if there are no entries.

fun <K, V> Map<out K, V>.minOfOrNull(
    selector: (Entry<K, V>) -> Double
): Double?
fun <K, V> Map<out K, V>.minOfOrNull(
    selector: (Entry<K, V>) -> Float
): Float?
fun <K, V, R : Comparable<R>> Map<out K, V>.minOfOrNull(
    selector: (Entry<K, V>) -> R
): R?
Common
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Native
1.4

minOfWith

Returns the smallest value according to the provided comparator among all values produced by selector function applied to each entry in the map.

fun <K, V, R> Map<out K, V>.minOfWith(
    comparator: Comparator<in R>,
    selector: (Entry<K, V>) -> R
): R
Common
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Native
1.4

minOfWithOrNull

Returns the smallest value according to the provided comparator among all values produced by selector function applied to each entry in the map or null if there are no entries.

fun <K, V, R> Map<out K, V>.minOfWithOrNull(
    comparator: Comparator<in R>,
    selector: (Entry<K, V>) -> R
): R?
Common
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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
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Native
1.1

minusAssign

Removes the entry with the given key from this mutable map.

operator fun <K, V> MutableMap<K, V>.minusAssign(key: K)

Removes all entries the keys of which are contained in the given keys collection from this mutable map.

operator fun <K, V> MutableMap<K, V>.minusAssign(
    keys: Iterable<K>)

Removes all entries the keys of which are contained in the given keys array from this mutable map.

operator fun <K, V> MutableMap<K, V>.minusAssign(
    keys: Array<out K>)

Removes all entries from the keys of which are contained in the given keys sequence from this mutable map.

operator fun <K, V> MutableMap<K, V>.minusAssign(
    keys: Sequence<K>)
Common
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Native
1.7

minWith

Returns the first entry having the smallest value according to the provided comparator.

fun <K, V> Map<out K, V>.minWith(
    comparator: Comparator<in Entry<K, V>>
): Entry<K, V>
Common
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JS
Native
1.4

minWithOrNull

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>.minWithOrNull(
    comparator: Comparator<in Entry<K, V>>
): Entry<K, V>?
Common
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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
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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
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Native
1.4

onEachIndexed

Performs the given action on each entry, providing sequential index with the entry, and returns the map itself afterwards.

fun <K, V, M : Map<out K, V>> M.onEachIndexed(
    action: (index: Int, Entry<K, V>) -> Unit
): M
Common
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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>
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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
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1.0

plusAssign

Appends or replaces the given pair in this mutable map.

operator fun <K, V> MutableMap<in K, in V>.plusAssign(
    pair: Pair<K, V>)

Appends or replaces all pairs from the given collection of pairs in this mutable map.

operator fun <K, V> MutableMap<in K, in V>.plusAssign(
    pairs: Iterable<Pair<K, V>>)

Appends or replaces all pairs from the given array of pairs in this mutable map.

operator fun <K, V> MutableMap<in K, in V>.plusAssign(
    pairs: Array<out Pair<K, V>>)

Appends or replaces all pairs from the given sequence of pairs in this mutable map.

operator fun <K, V> MutableMap<in K, in V>.plusAssign(
    pairs: Sequence<Pair<K, V>>)

Appends or replaces all entries from the given map in this mutable map.

operator fun <K, V> MutableMap<in K, in V>.plusAssign(
    map: Map<K, V>)
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1.0

putAll

Puts all the given pairs into this MutableMap with the first component in the pair being the key and the second the value.

fun <K, V> MutableMap<in K, in V>.putAll(
    pairs: Array<out Pair<K, V>>)

Puts all the elements of the given collection into this MutableMap with the first component in the pair being the key and the second the value.

fun <K, V> MutableMap<in K, in V>.putAll(
    pairs: Iterable<Pair<K, V>>)

Puts all the elements of the given sequence into this MutableMap with the first component in the pair being the key and the second the value.

fun <K, V> MutableMap<in K, in V>.putAll(
    pairs: Sequence<Pair<K, V>>)
Common
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1.0

remove

Removes the specified key and its corresponding value from this map.

fun <K, V> MutableMap<out K, V>.remove(key: K): V?
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1.0

set

Allows to use the index operator for storing values in a mutable map.

operator fun <K, V> MutableMap<K, V>.set(key: K, value: V)
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1.0

setValue

Stores the value of the property for the given object in this mutable map.

operator fun <V> MutableMap<in String, in V>.setValue(
    thisRef: Any?,
    property: KProperty<*>,
    value: V)
Common
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1.0

toList

Returns a List containing all key-value pairs.

fun <K, V> Map<out K, V>.toList(): List<Pair<K, V>>
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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
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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
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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>

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

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