kotlin-stdlib/kotlin.collections/HashMap

HashMap

expect class HashMap<K, V> : MutableMap<K, V> (source)

actual typealias HashMap = HashMap<K, V>

actual open class HashMap<K, V> : AbstractMutableMap<K, V> , MutableMap<K, V>

Hash table based implementation of the MutableMap interface.

This implementation makes no guarantees regarding the order of enumeration of keys, values and entries collections.

actual class HashMap<K, V> : MutableMap<K, V>

Constructors

HashMap

expect fun HashMap()

actual fun HashMap()

Constructs an empty HashMap instance.

actual fun HashMap()

HashMap

expect fun HashMap(initialCapacity: Int)

actual fun HashMap(initialCapacity: Int)

HashMap

expect fun HashMap(initialCapacity: Int, loadFactor: Float)

actual fun HashMap(initialCapacity: Int, loadFactor: Float = 0.0f)

Constructs an empty HashMap instance.

actual fun HashMap(initialCapacity: Int, loadFactor: Float)

HashMap

expect fun <K, V> HashMap(original: Map<out K, V>)

actual fun <K, V> HashMap(original: Map<out K, V>)

Constructs an instance of HashMap filled with the contents of the specified original map.

actual fun <K, V> HashMap(original: Map<out K, V>)

Functions

clear

expect open override fun clear()

actual open override fun clear()

Removes all elements from this map.

actual open override fun clear()

Removes all elements from this map.

containsKey

expect open override fun containsKey(key: K): Boolean

actual open override fun containsKey(key: K): Boolean

Returns true if the map contains the specified key.

actual open override fun containsKey(key: K): Boolean

Returns true if the map contains the specified key.

containsValue

expect open override fun containsValue(value: @UnsafeVariance V): Boolean

actual open override fun containsValue(value: V): Boolean

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

actual open override fun containsValue(value: V): Boolean

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

equals

open operator override fun equals(other: Any?): Boolean

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

open operator override fun equals(other: Any?): Boolean

get

expect open operator override fun get(key: K): V?

actual open operator override fun get(key: K): V?

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

actual open operator override fun get(key: K): V?

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

getOrDefault

open fun getOrDefault(key: K, defaultValue: V): V

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

Since Kotlin 1.1

open fun getOrDefault(key: K, defaultValue: V): V

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

Since Kotlin 1.1

hashCode

open override fun hashCode(): Int

Returns the hash code value for this map.

open override fun hashCode(): Int

isEmpty

expect open override fun isEmpty(): Boolean

open override fun isEmpty(): Boolean

Returns true if the map is empty (contains no elements), false otherwise.

actual open override fun isEmpty(): Boolean

Returns true if the map is empty (contains no elements), false otherwise.

put

expect open override fun put(key: K, value: V): V?

actual open override fun put(key: K, value: V): V?

Associates the specified value with the specified key in the map.

actual open override fun put(key: K, value: V): V?

Associates the specified value with the specified key in the map.

putAll

expect open override fun putAll(from: Map<out K, V>)

actual open override fun putAll(from: Map<out K, V>)

Updates this map with key/value pairs from the specified map from.

remove

expect open override fun remove(key: K): V?

actual open override fun remove(key: K): V?

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

open fun remove(key: K, value: V): Boolean

Removes the entry for the specified key only if it is mapped to the specified value.

Since Kotlin 1.1

actual open override fun remove(key: K): V?

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

open fun remove(key: K, value: V): Boolean

Removes the entry for the specified key only if it is mapped to the specified value.

Since Kotlin 1.1

toString

open override fun toString(): String

fun toString(entry: Map.Entry<K, V>): String

open override fun toString(): String

Properties

entries

expect open override val entries: MutableSet<MutableMap.MutableEntry<K, V>>

actual open override val entries: MutableSet<MutableMap.MutableEntry<K, V>>

Returns a MutableSet of all key/value pairs in this map.

actual open override val entries: MutableSet<MutableMap.MutableEntry<K, V>>

Returns a MutableSet of all key/value pairs in this map.

keys

expect open override val keys: MutableSet<K>

actual open override val keys: MutableSet<K>

Returns a MutableSet of all keys in this map.

size

expect open override val size: Int

actual open override val size: Int

Returns the number of key/value pairs in the map.

actual open override val size: Int

Returns the number of key/value pairs in the map.

values

expect open override val values: MutableCollection<V>

actual open override val values: MutableCollection<V>

Returns a MutableCollection of all values in this map. Note that this collection may contain duplicate values.

Inheritors

LinkedHashMap

Extensions

all

inline fun <K, V> Map<out K, V>.all(predicate: (Map.Entry<K, V>) -> Boolean): Boolean

Returns true if all entries match the given predicate.

any

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

Returns true if map has at least one entry.

inline fun <K, V> Map<out K, V>.any(predicate: (Map.Entry<K, V>) -> Boolean): Boolean

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

asIterable

inline fun <K, V> Map<out K, V>.asIterable(): Iterable<Map.Entry<K, V>>

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

asSequence

fun <K, V> Map<out K, V>.asSequence(): Sequence<Map.Entry<K, V>>

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

contains

inline operator fun <K, V> Map<out K, V>.contains(key: K): Boolean

Checks if the map contains the given key.

containsKey

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

Returns true if the map contains the specified key.

containsValue

inline fun <K, V> Map<K, V>.containsValue(value: V): Boolean

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

count

inline fun <K, V> Map<out K, V>.count(): Int

Returns the number of entries in this map.

inline fun <K, V> Map<out K, V>.count(predicate: (Map.Entry<K, V>) -> Boolean): Int

Returns the number of entries matching the given predicate.

filter

inline fun <K, V> Map<out K, V>.filter(predicate: (Map.Entry<K, V>) -> Boolean): Map<K, V>

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

filterKeys

inline fun <K, V> Map<out K, V>.filterKeys(predicate: (K) -> Boolean): Map<K, V>

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

filterNot

inline fun <K, V> Map<out K, V>.filterNot(predicate: (Map.Entry<K, V>) -> Boolean): Map<K, V>

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

filterNotTo

inline fun <K, V, M : MutableMap<in K, in V>> Map<out K, V>.filterNotTo(destination: M, predicate: (Map.Entry<K, V>) -> Boolean): M

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

filterTo

inline fun <K, V, M : MutableMap<in K, in V>> Map<out K, V>.filterTo(destination: M, predicate: (Map.Entry<K, V>) -> Boolean): M

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

filterValues

inline fun <K, V> Map<out K, V>.filterValues(predicate: (V) -> Boolean): Map<K, V>

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

firstNotNullOf

inline fun <K, V, R : Any> Map<out K, V>.firstNotNullOf(transform: (Map.Entry<K, V>) -> R?): R

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.

firstNotNullOfOrNull

inline fun <K, V, R : Any> Map<out K, V>.firstNotNullOfOrNull(transform: (Map.Entry<K, V>) -> R?): R?

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.

flatMap

inline fun <K, V, R> Map<out K, V>.flatMap(transform: (Map.Entry<K, V>) -> Iterable<R>): List<R>

@JvmName(name = "flatMapSequence")

inline fun <K, V, R> Map<out K, V>.flatMap(transform: (Map.Entry<K, V>) -> Sequence<R>): List<R>

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

flatMapTo

inline fun <K, V, R, C : MutableCollection<in R>> Map<out K, V>.flatMapTo(destination: C, transform: (Map.Entry<K, V>) -> Iterable<R>): C

@JvmName(name = "flatMapSequenceTo")

inline fun <K, V, R, C : MutableCollection<in R>> Map<out K, V>.flatMapTo(destination: C, transform: (Map.Entry<K, V>) -> Sequence<R>): C

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

forEach

inline fun <K, V> Map<out K, V>.forEach(action: (Map.Entry<K, V>) -> Unit)

Performs the given action on each entry.

get

inline operator fun <K, V> Map<out K, V>.get(key: K): V?

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

getOrDefault

inline fun <K, V> Map<out K, V>.getOrDefault(key: K, defaultValue: V): V

Returns the value to which the specified key is mapped, or defaultValue if this map contains no mapping for the key.

getOrElse

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

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

getOrPut

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

Returns the value for the given key. If the key is not found in the map, calls the defaultValue function, puts its result into the map under the given key and returns it.

getValue

@JvmName(name = "getVar")

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

Returns the value of the property for the given object from this mutable map.

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

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

fun <K, V> Map<K, V>.getValue(key: K): V

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

isNotEmpty

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

Returns true if this map is not empty.

isNullOrEmpty

inline fun <K, V> Map<out K, V>?.isNullOrEmpty(): Boolean

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

iterator

@JvmName(name = "mutableIterator")

inline operator fun <K, V> MutableMap<K, V>.iterator(): MutableIterator<MutableMap.MutableEntry<K, V>>

Returns a MutableIterator over the mutable entries in the MutableMap.

inline operator fun <K, V> Map<out K, V>.iterator(): Iterator<Map.Entry<K, V>>

Returns an Iterator over the entries in the Map.

map

inline fun <K, V, R> Map<out K, V>.map(transform: (Map.Entry<K, V>) -> R): List<R>

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

mapKeys

inline fun <K, V, R> Map<out K, V>.mapKeys(transform: (Map.Entry<K, V>) -> R): Map<R, V>

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.

mapKeysTo

inline fun <K, V, R, M : MutableMap<in R, in V>> Map<out K, V>.mapKeysTo(destination: M, transform: (Map.Entry<K, V>) -> R): M

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.

mapNotNull

inline fun <K, V, R : Any> Map<out K, V>.mapNotNull(transform: (Map.Entry<K, V>) -> R?): List<R>

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

mapNotNullTo

inline fun <K, V, R : Any, C : MutableCollection<in R>> Map<out K, V>.mapNotNullTo(destination: C, transform: (Map.Entry<K, V>) -> R?): C

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

mapTo

inline fun <K, V, R, C : MutableCollection<in R>> Map<out K, V>.mapTo(destination: C, transform: (Map.Entry<K, V>) -> R): C

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

mapValues

inline fun <K, V, R> Map<out K, V>.mapValues(transform: (Map.Entry<K, V>) -> R): Map<K, R>

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.

mapValuesTo

inline fun <K, V, R, M : MutableMap<in K, in R>> Map<out K, V>.mapValuesTo(destination: M, transform: (Map.Entry<K, V>) -> R): M

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.

maxBy

inline fun <K, V, R : Comparable<R>> Map<out K, V>.~~maxBy~~(selector: (Map.Entry<K, V>) -> R): Map.Entry<K, V>?

maxByOrNull

inline fun <K, V, R : Comparable<R>> Map<out K, V>.maxByOrNull(selector: (Map.Entry<K, V>) -> R): Map.Entry<K, V>?

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

maxOf

inline fun <K, V> Map<out K, V>.maxOf(selector: (Map.Entry<K, V>) -> Double): Double

inline fun <K, V> Map<out K, V>.maxOf(selector: (Map.Entry<K, V>) -> Float): Float

inline fun <K, V, R : Comparable<R>> Map<out K, V>.maxOf(selector: (Map.Entry<K, V>) -> R): R

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

maxOfOrNull

inline fun <K, V> Map<out K, V>.maxOfOrNull(selector: (Map.Entry<K, V>) -> Double): Double?

inline fun <K, V> Map<out K, V>.maxOfOrNull(selector: (Map.Entry<K, V>) -> Float): Float?

inline fun <K, V, R : Comparable<R>> Map<out K, V>.maxOfOrNull(selector: (Map.Entry<K, V>) -> R): R?

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.

maxOfWith

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

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

maxOfWithOrNull

inline fun <K, V, R> Map<out K, V>.maxOfWithOrNull(comparator: Comparator<in R>, selector: (Map.Entry<K, V>) -> R): R?

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.

maxWith

inline fun <K, V> Map<out K, V>.~~maxWith~~(comparator: Comparator<in Map.Entry<K, V>>): Map.Entry<K, V>?

maxWithOrNull

inline fun <K, V> Map<out K, V>.maxWithOrNull(comparator: Comparator<in Map.Entry<K, V>>): Map.Entry<K, V>?

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

minBy

inline fun <K, V, R : Comparable<R>> Map<out K, V>.~~minBy~~(selector: (Map.Entry<K, V>) -> R): Map.Entry<K, V>?

minByOrNull

inline fun <K, V, R : Comparable<R>> Map<out K, V>.minByOrNull(selector: (Map.Entry<K, V>) -> R): Map.Entry<K, V>?

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

minOf

inline fun <K, V> Map<out K, V>.minOf(selector: (Map.Entry<K, V>) -> Double): Double

inline fun <K, V> Map<out K, V>.minOf(selector: (Map.Entry<K, V>) -> Float): Float

inline fun <K, V, R : Comparable<R>> Map<out K, V>.minOf(selector: (Map.Entry<K, V>) -> R): R

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

minOfOrNull

inline fun <K, V> Map<out K, V>.minOfOrNull(selector: (Map.Entry<K, V>) -> Double): Double?

inline fun <K, V> Map<out K, V>.minOfOrNull(selector: (Map.Entry<K, V>) -> Float): Float?

inline fun <K, V, R : Comparable<R>> Map<out K, V>.minOfOrNull(selector: (Map.Entry<K, V>) -> R): R?

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.

minOfWith

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

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

minOfWithOrNull

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

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.

minus

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 the entry with the given key.

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 collection.

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 array.

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

minusAssign

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

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

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

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

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

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

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

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

minWith

fun <K, V> Map<out K, V>.~~minWith~~(comparator: Comparator<in Map.Entry<K, V>>): Map.Entry<K, V>?

minWithOrNull

inline fun <K, V> Map<out K, V>.minWithOrNull(comparator: Comparator<in Map.Entry<K, V>>): Map.Entry<K, V>?

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

none

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

Returns true if the map has no entries.

inline fun <K, V> Map<out K, V>.none(predicate: (Map.Entry<K, V>) -> Boolean): Boolean

Returns true if no entries match the given predicate.

orEmpty

inline fun <K, V> Map<K, V>?.orEmpty(): Map<K, V>

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

plus

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 an entry to this map from a given key-value pair.

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 collection 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 array 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 a given sequence of key-value pairs.

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

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

plusAssign

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

Appends or replaces the given pair in this mutable map.

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

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

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

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

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

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

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

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

putAll

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

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: Iterable<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: Sequence<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.

remove

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

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

inline fun <K, V> MutableMap<out K, out V>.remove(key: K, value: V): Boolean

Removes the entry for the specified key only if it is currently mapped to the specified value.

set

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

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

setValue

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

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

toList

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

Returns a List containing all key-value pairs.

toMap

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

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

fun <K, V, M : MutableMap<in K, in V>> Map<out K, V>.toMap(destination: M): M

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

toMutableMap

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

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

toProperties

inline fun Map<String, String>.toProperties(): Properties

Converts this Map to a Properties object.

toSortedMap

fun <K : Comparable<K>, V> Map<out K, V>.toSortedMap(): SortedMap<K, V>

Converts this Map to a SortedMap. The resulting SortedMap determines the equality and order of keys according to their natural sorting order.

fun <K, V> Map<out K, V>.toSortedMap(comparator: Comparator<in K>): SortedMap<K, V>

Converts this Map to a SortedMap. The resulting SortedMap determines the equality and order of keys according to the sorting order provided by the given comparator.

withDefault

@JvmName(name = "withDefaultMutable")

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

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