Represents a key/value pair held by a MutableMap.

interface MutableEntry<K, V> : Entry<K, V>

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

abstract val entries: MutableSet<MutableEntry<K, V>>

Returns a MutableSet of all keys in this map.

abstract val keys: MutableSet<K>

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

abstract val values: MutableCollection<V>

Removes all elements from this map.

abstract fun clear()

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

abstract fun put(key: K, value: V): V?

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

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

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

abstract fun remove(key: K): V?

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

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

Returns true if all entries match the given predicate.

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

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

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>>

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>>

Checks if the map contains the given key.

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

Returns true if the map contains the specified key.

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

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

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

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

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>

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>

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>

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

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

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>

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>

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

Performs the given action on each entry.

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

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?

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

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.

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

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

operator fun <V, V1 : V> MutableMap<in String, out 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

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

Returns true if this map is not empty.

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

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

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

Returns a MutableIterator over the mutable entries in the MutableMap.

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

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>

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>

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

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>

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

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

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>

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

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>?

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>?

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>?

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>

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>)

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>?

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

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

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

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

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>)

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>>)

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

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

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

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

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)

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)

Returns a List containing all key-value pairs.

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

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

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>

Converts this Map to a Properties object.

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

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.

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

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>

Provides a skeletal implementation of the MutableMap interface.

abstract class AbstractMutableMap<K, V> : MutableMap<K, V>

abstract class AbstractMutableMap<K, V> : 
    MutableMap<K, V>, 
    AbstractMap<K, V>

abstract class AbstractMutableMap<K, V> : 
    AbstractMap<K, V>, 
    MutableMap<K, V>

Hash table based implementation of the MutableMap interface.

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

typealias HashMap<K, V> = HashMap<K, V>

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

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

class LinkedHashMap<K, V> : MutableMap<K, V>

typealias LinkedHashMap<K, V> = LinkedHashMap<K, V>

open class LinkedHashMap<K, V> : 
    HashMap<K, V>, 
    MutableMap<K, V>

typealias LinkedHashMap<K, V> = HashMap<K, V>