Compukters Core/kotlin.collections/MutableMap

MutableMap

interface MutableMap<K, V> : Map<K, V> (source)

A map supporting association replacement, removal and clearing.

Read-only Map aliases observe the same mutations. An equal existing key is associated with the new value rather than creating a second association.

Type Parameters

key type.

value type.

Inheritors

HashMap

Types

MutableEntry

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

A map entry whose associated value can be replaced without changing its key.

Properties

entries

abstract val entries: Set<Map.Entry<K, V>>

Read-only set of this map's key-value entries.

keys

abstract val keys: Set<K>

Read-only set of this map's keys.

size

abstract val size: Int

Number of key-value associations in this map.

values

abstract val values: Collection<V>

Read-only collection of this map's values, retaining duplicates from different keys.

Functions

clear

abstract fun clear()

Removes all associations from this map.

contains

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

Checks key membership using key in map syntax.

containsKey

abstract fun containsKey(key: K): Boolean

Checks whether an association exists for key, including one whose value is null.

containsValue

abstract fun containsValue(value: V): Boolean

Checks whether any stored value equals value.

get

abstract operator fun get(key: K): V?

Returns the value associated with key, or null when the key is absent.

getOrPut

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

Returns a non-null value for key, or computes and stores a default value.

isEmpty

abstract fun isEmpty(): Boolean

Checks whether this map contains no associations.

isNotEmpty

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

Checks whether this map contains at least one association.

iterator

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

Returns an iterator over this map's entries, enabling for ((key, value) in map).

put

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

Associates key with value, replacing an existing value for an equal key.

putAll

abstract fun putAll(p0: Map<out K?, out V?>?)

set

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

Associates key with value using indexed assignment, discarding the previous value.