# AbstractMap Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) # AbstractMap ``` abstract class AbstractMap : MutableMap ``` |---|------------------------------------------------------------------------------------------------| | [kotlin.Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html) || | ↳ | [java.util.AbstractMap](https://developer.android.com/reference/kotlin/java/util/AbstractMap#) | |-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Known Direct Subclasses [ConcurrentHashMap](https://developer.android.com/reference/kotlin/java/util/concurrent/ConcurrentHashMap),[ConcurrentSkipListMap](https://developer.android.com/reference/kotlin/java/util/concurrent/ConcurrentSkipListMap),[EnumMap](https://developer.android.com/reference/kotlin/java/util/EnumMap),[HashMap](https://developer.android.com/reference/kotlin/java/util/HashMap),[IdentityHashMap](https://developer.android.com/reference/kotlin/java/util/IdentityHashMap),[TreeMap](https://developer.android.com/reference/kotlin/java/util/TreeMap),[WeakHashMap](https://developer.android.com/reference/kotlin/java/util/WeakHashMap) |--------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------| | [ConcurrentHashMap](https://developer.android.com/reference/kotlin/java/util/concurrent/ConcurrentHashMap) | A hash table supporting full concurrency of retrievals and high expected concurrency for updates. | | [ConcurrentSkipListMap](https://developer.android.com/reference/kotlin/java/util/concurrent/ConcurrentSkipListMap) | A scalable concurrent[ConcurrentNavigableMap](https://developer.android.com/reference/kotlin/java/util/concurrent/ConcurrentNavigableMap)implementation. | | [EnumMap](https://developer.android.com/reference/kotlin/java/util/EnumMap) | A specialized[Map](https://developer.android.com/reference/kotlin/java/util/Map)implementation for use with enum type keys. | | [HashMap](https://developer.android.com/reference/kotlin/java/util/HashMap) | Hash table based implementation of the`Map`interface. | | [IdentityHashMap](https://developer.android.com/reference/kotlin/java/util/IdentityHashMap) | This class implements the`Map`interface with a hash table, using reference-equality in place of object-equality when comparing keys (and values). | | [TreeMap](https://developer.android.com/reference/kotlin/java/util/TreeMap) | A Red-Black tree based[NavigableMap](https://developer.android.com/reference/kotlin/java/util/NavigableMap)implementation. | | [WeakHashMap](https://developer.android.com/reference/kotlin/java/util/WeakHashMap) | Hash table based implementation of the`Map`interface, with*weak keys*. | | |---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Known Indirect Subclasses [LinkedHashMap](https://developer.android.com/reference/kotlin/java/util/LinkedHashMap) |-----------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------| | [LinkedHashMap](https://developer.android.com/reference/kotlin/java/util/LinkedHashMap) | Hash table and linked list implementation of the`Map`interface, with well-defined encounter order. | | This class provides a skeletal implementation of the`Map`interface, to minimize the effort required to implement this interface. To implement an unmodifiable map, the programmer needs only to extend this class and provide an implementation for the`entrySet`method, which returns a set-view of the map's mappings. Typically, the returned set will, in turn, be implemented atop`AbstractSet`. This set should not support the`add`or`remove`methods, and its iterator should not support the`remove`method. To implement a modifiable map, the programmer must additionally override this class's`put`method (which otherwise throws an`UnsupportedOperationException`), and the iterator returned by`entrySet().iterator()`must additionally implement its`remove`method. The programmer should generally provide a void (no argument) and map constructor, as per the recommendation in the`Map`interface specification. The documentation for each non-abstract method in this class describes its implementation in detail. Each of these methods may be overridden if the map being implemented admits a more efficient implementation. This class is a member of the[Java Collections Framework](https://developer.android.com//reference/java/util/package-summary.html#CollectionsFramework). ## Summary | Nested classes || |------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | open | [SimpleEntry](https://developer.android.com/reference/kotlin/java/util/AbstractMap.SimpleEntry) An Entry maintaining a key and a value. | | open | [SimpleImmutableEntry](https://developer.android.com/reference/kotlin/java/util/AbstractMap.SimpleImmutableEntry) An unmodifiable Entry maintaining a key and a value. | | Protected constructors || |-------------------------------------------------------------------------------------------------------------------------|---| | [AbstractMap](https://developer.android.com/reference/kotlin/java/util/AbstractMap#AbstractMap())`()` Sole constructor. | | Public methods || |----------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | open[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [clear](https://developer.android.com/reference/kotlin/java/util/AbstractMap#clear())`()` Removes all of the mappings from this map (optional operation). | | open[Boolean](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-boolean/index.html) | [containsKey](https://developer.android.com/reference/kotlin/java/util/AbstractMap#containsKey(java.util.AbstractMap.K))`(`key:` `K?`)` Returns`true`if this map contains a mapping for the specified key. | | open[Boolean](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-boolean/index.html) | [containsValue](https://developer.android.com/reference/kotlin/java/util/AbstractMap#containsValue(java.util.AbstractMap.V))`(`value:` `V?`)` Returns`true`if this map maps one or more keys to the specified value. | | open[Boolean](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-boolean/index.html) | [equals](https://developer.android.com/reference/kotlin/java/util/AbstractMap#equals(kotlin.Any))`(`other:` `[Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html)?`)` Compares the specified object with this map for equality. | | openV? | [get](https://developer.android.com/reference/kotlin/java/util/AbstractMap#get(java.util.AbstractMap.K))`(`key:` `K?`)` Returns the value to which the specified key is mapped, or`null`if this map contains no mapping for the key. | | open[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [hashCode](https://developer.android.com/reference/kotlin/java/util/AbstractMap#hashCode())`()` Returns the hash code value for this map. | | open[Boolean](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-boolean/index.html) | [isEmpty](https://developer.android.com/reference/kotlin/java/util/AbstractMap#isEmpty())`()` Returns`true`if this map contains no key-value mappings. | | openV? | [put](https://developer.android.com/reference/kotlin/java/util/AbstractMap#put(java.util.AbstractMap.K,%20java.util.AbstractMap.V))`(`key:` `K`, `value:` `V`)` Associates the specified value with the specified key in this map (optional operation). | | open[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [putAll](https://developer.android.com/reference/kotlin/java/util/AbstractMap#putAll(kotlin.collections.Map))`(`from:` `[Map](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-map/index.html)`)` Copies all of the mappings from the specified map to this map (optional operation). | | openV? | [remove](https://developer.android.com/reference/kotlin/java/util/AbstractMap#remove(java.util.AbstractMap.K))`(`key:` `K?`)` Removes the mapping for a key from this map if it is present (optional operation). | | open[String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html) | [toString](https://developer.android.com/reference/kotlin/java/util/AbstractMap#toString())`()` Returns a string representation of this map. | | Protected methods || |--------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | open[Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html) | [clone](https://developer.android.com/reference/kotlin/java/util/AbstractMap#clone())`()` Returns a shallow copy of this`AbstractMap`instance: the keys and values themselves are not cloned. | | Properties || |------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | abstract[MutableSet](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-mutable-set/index.html)\<[MutableEntry](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-mutable-map/-mutable-entry/index.html)\\> | [entries](https://developer.android.com/reference/kotlin/java/util/AbstractMap#entries:kotlin.collections.MutableSet)
| | open[MutableSet](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-mutable-set/index.html)\ | [keys](https://developer.android.com/reference/kotlin/java/util/AbstractMap#keys:kotlin.collections.MutableSet) Returns a[Set](https://developer.android.com/reference/kotlin/java/util/Set)view of the keys contained in this map. | | open[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [size](https://developer.android.com/reference/kotlin/java/util/AbstractMap#size:kotlin.Int) Returns the number of key-value mappings in this map. | | open[MutableCollection](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-mutable-collection/index.html)\ | [values](https://developer.android.com/reference/kotlin/java/util/AbstractMap#values:kotlin.collections.MutableCollection) Returns a[Collection](https://developer.android.com/reference/kotlin/java/util/Collection)view of the values contained in this map. | ## Protected constructors ### AbstractMap Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` protected AbstractMap() ``` Sole constructor. (For invocation by subclass constructors, typically implicit.) ## Public methods ### clear Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` open fun clear(): Unit ``` Removes all of the mappings from this map (optional operation). The map will be empty after this call returns. | Exceptions || |-------------------------------------------|-----------------------------------------------------| | `java.lang.UnsupportedOperationException` | if the`clear`operation is not supported by this map | ### containsKey Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` open fun containsKey(key: K?): Boolean ``` Returns`true`if this map contains a mapping for the specified key. More formally, returns`true`if and only if this map contains a mapping for a key`k`such that`Objects.equals(key, k)`. (There can be at most one such mapping.) | Parameters || |-------|---------------------------------------------------| | `key` | K?:key whose presence in this map is to be tested | | Return || |------------------------------------------------------------------------------------|------------------------------------------------------------| | [Boolean](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-boolean/index.html) | `true`if this map contains a mapping for the specified key | | Exceptions || |----------------------------------|---------------------------------------------------------------------------------------------| | `java.lang.ClassCastException` | if the key is of an inappropriate type for this map (java.util.Collection#) | | `java.lang.NullPointerException` | if the specified key is null and this map does not permit null keys (java.util.Collection#) | ### containsValue Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` open fun containsValue(value: V?): Boolean ``` Returns`true`if this map maps one or more keys to the specified value. More formally, returns`true`if and only if this map contains at least one mapping to a value`v`such that`Objects.equals(value, v)`. This operation will probably require time linear in the map size for most implementations of the`Map`interface. | Parameters || |---------|-----------------------------------------------------| | `value` | V?:value whose presence in this map is to be tested | | Return || |------------------------------------------------------------------------------------|----------------------------------------------------------------| | [Boolean](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-boolean/index.html) | `true`if this map maps one or more keys to the specified value | | Exceptions || |----------------------------------|-------------------------------------------------------------------------------------------------| | `java.lang.ClassCastException` | if the value is of an inappropriate type for this map (java.util.Collection#) | | `java.lang.NullPointerException` | if the specified value is null and this map does not permit null values (java.util.Collection#) | ### equals Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` open fun equals(other: Any?): Boolean ``` Compares the specified object with this map for equality. Returns`true`if the given object is also a map and the two maps represent the same mappings. More formally, two maps`m1`and`m2`represent the same mappings if`m1.entrySet().equals(m2.entrySet())`. This ensures that the`equals`method works properly across different implementations of the`Map`interface. | Parameters || |-------|--------------------------------------------------| | `obj` | the reference object with which to compare. | | `o` | object to be compared for equality with this map | | Return || |------------------------------------------------------------------------------------|----------------------------------------------------| | [Boolean](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-boolean/index.html) | `true`if the specified object is equal to this map | ### get Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` open fun get(key: K?): V? ``` Returns the value to which the specified key is mapped, or`null`if this map contains no mapping for the key. More formally, if this map contains a mapping from a key`k`to a value`v`such that`Objects.equals(key, k)`, then this method returns`v`; otherwise it returns`null`. (There can be at most one such mapping.) If this map permits null values, then a return value of`null`does not*necessarily* indicate that the map contains no mapping for the key; it's also possible that the map explicitly maps the key to`null`. The[containsKey](https://developer.android.com/reference/kotlin/java/util/Map#containsKey(kotlin.Any))operation may be used to distinguish these two cases. | Parameters || |-------|-----------------------------------------------------| | `key` | K?:the key whose associated value is to be returned | | Return || |----|-----------------------------------------------------------------------------------------------------| | V? | the value to which the specified key is mapped, or`null`if this map contains no mapping for the key | | Exceptions || |----------------------------------|---------------------------------------------------------------------------------------------| | `java.lang.ClassCastException` | if the key is of an inappropriate type for this map (java.util.Collection#) | | `java.lang.NullPointerException` | if the specified key is null and this map does not permit null keys (java.util.Collection#) | ### hashCode Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` open fun hashCode(): Int ``` Returns the hash code value for this map. The hash code of a map is defined to be the sum of the hash codes of each entry in the map's`entrySet()`view. This ensures that`m1.equals(m2)`implies that`m1.hashCode()==m2.hashCode()`for any two maps`m1`and`m2`, as required by the general contract of[Object.hashCode](https://developer.android.com/reference/kotlin/java/lang/Object.html#hashCode()). | Return || |----------------------------------------------------------------------------|----------------------------------| | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | the hash code value for this map | **See Also** - [java.util.Map.Entry#hashCode()](https://developer.android.com/reference/kotlin/java/util/AbstractMap#) - [java.lang.Object#equals(Object)](https://developer.android.com/reference/kotlin/java/lang/Object.html#equals(kotlin.Any)) ### isEmpty Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` open fun isEmpty(): Boolean ``` Returns`true`if this map contains no key-value mappings. | Return || |------------------------------------------------------------------------------------|--------------------------------------------------| | [Boolean](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-boolean/index.html) | `true`if this map contains no key-value mappings | ### put Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` open fun put(     key: K,     value: V ): V? ``` Associates the specified value with the specified key in this map (optional operation). If the map previously contained a mapping for the key, the old value is replaced by the specified value. (A map`m`is said to contain a mapping for a key`k`if and only if[m.containsKey(k)](https://developer.android.com/reference/kotlin/java/util/Map#containsKey(kotlin.Any))would return`true`.) | Parameters || |---------|----------------------------------------------------------| | `key` | K:key with which the specified value is to be associated | | `value` | V:value to be associated with the specified key | | Return || |----|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | V? | the previous value associated with`key`, or`null`if there was no mapping for`key`. (A`null`return can also indicate that the map previously associated`null`with`key`, if the implementation supports`null`values.) | | Exceptions || |-------------------------------------------|------------------------------------------------------------------------------------------| | `java.lang.UnsupportedOperationException` | if the`put`operation is not supported by this map | | `java.lang.ClassCastException` | if the class of the specified key or value prevents it from being stored in this map | | `java.lang.NullPointerException` | if the specified key or value is null and this map does not permit null keys or values | | `java.lang.IllegalArgumentException` | if some property of the specified key or value prevents it from being stored in this map | ### putAll Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` open fun putAll(from: Map): Unit ``` Copies all of the mappings from the specified map to this map (optional operation). The effect of this call is equivalent to that of calling[put(k, v)](https://developer.android.com/reference/kotlin/java/util/Map#put(java.util.Map.K,%20java.util.Map.V))on this map once for each mapping from key`k`to value`v`in the specified map. The behavior of this operation is undefined if the specified map is modified while the operation is in progress. If the specified map has a defined[encounter order](https://developer.android.com/reference/kotlin/java/util/SequencedCollection#encounter), processing of its mappings generally occurs in that order. | Parameters || |-----|-----------------------------------| | `m` | mappings to be stored in this map | | Exceptions || |-------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------| | `java.lang.UnsupportedOperationException` | if the`putAll`operation is not supported by this map | | `java.lang.ClassCastException` | if the class of a key or value in the specified map prevents it from being stored in this map | | `java.lang.NullPointerException` | if the specified map is null, or if this map does not permit null keys or values, and the specified map contains null keys or values | | `java.lang.IllegalArgumentException` | if some property of a key or value in the specified map prevents it from being stored in this map | ### remove Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` open fun remove(key: K?): V? ``` Removes the mapping for a key from this map if it is present (optional operation). More formally, if this map contains a mapping from key`k`to value`v`such that`Objects.equals(key, k)`, that mapping is removed. (The map can contain at most one such mapping.) Returns the value to which this map previously associated the key, or`null`if the map contained no mapping for the key. If this map permits null values, then a return value of`null`does not*necessarily* indicate that the map contained no mapping for the key; it's also possible that the map explicitly mapped the key to`null`. The map will not contain a mapping for the specified key once the call returns. | Parameters || |-------|----------------------------------------------------| | `key` | K?:key whose mapping is to be removed from the map | | Return || |----|------------------------------------------------------------------------------------| | V? | the previous value associated with`key`, or`null`if there was no mapping for`key`. | | Exceptions || |-------------------------------------------|---------------------------------------------------------------------------------------------| | `java.lang.UnsupportedOperationException` | if the`remove`operation is not supported by this map | | `java.lang.ClassCastException` | if the key is of an inappropriate type for this map (java.util.Collection#) | | `java.lang.NullPointerException` | if the specified key is null and this map does not permit null keys (java.util.Collection#) | ### toString Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` open fun toString(): String ``` Returns a string representation of this map. The string representation consists of a list of key-value mappings in the order returned by the map's`entrySet`view's iterator, enclosed in braces (`"{}"`). Adjacent mappings are separated by the characters`", "`(comma and space). Each key-value mapping is rendered as the key followed by an equals sign (`"="`) followed by the associated value. Keys and values are converted to strings as by[String.valueOf(Object)](https://developer.android.com/reference/kotlin/java/lang/String.html#valueOf(kotlin.Any)). | Return || |----------------------------------------------------------------------------------|-------------------------------------| | [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html) | a string representation of this map | ## Protected methods ### clone Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` protected open fun clone(): Any ``` Returns a shallow copy of this`AbstractMap`instance: the keys and values themselves are not cloned. | Return || |----------------------------------------------------------------------------|----------------------------| | [Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html) | a shallow copy of this map | | Exceptions || |----------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | `java.lang.CloneNotSupportedException` | if the object's class does not support the`Cloneable`interface. Subclasses that override the`clone`method can also throw this exception to indicate that an instance cannot be cloned. | ## Properties ### entries Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` abstract val entries: MutableSet> ``` | Return || |---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------| | [MutableSet](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-mutable-set/index.html)<[MutableEntry](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-mutable-map/-mutable-entry/index.html)> | a set view of the mappings contained in this map | ### keys Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` open val keys: MutableSet ``` Returns a[Set](https://developer.android.com/reference/kotlin/java/util/Set)view of the keys contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own`remove`operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the`Iterator.remove`,`Set.remove`,`removeAll`,`retainAll`, and`clear`operations. It does not support the`add`or`addAll`operations. | Return || |----------------------------------------------------------------------------------------------------------|----------------------------------------------| | [MutableSet](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-mutable-set/index.html) | a set view of the keys contained in this map | ### size Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` open val size: Int ``` Returns the number of key-value mappings in this map. If the map contains more than`Integer.MAX_VALUE`elements, returns`Integer.MAX_VALUE`. | Return || |----------------------------------------------------------------------------|----------------------------------------------| | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | the number of key-value mappings in this map | ### values Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` open val values: MutableCollection ``` Returns a[Collection](https://developer.android.com/reference/kotlin/java/util/Collection)view of the values contained in this map. The collection is backed by the map, so changes to the map are reflected in the collection, and vice-versa. If the map is modified while an iteration over the collection is in progress (except through the iterator's own`remove`operation), the results of the iteration are undefined. The collection supports element removal, which removes the corresponding mapping from the map, via the`Iterator.remove`,`Collection.remove`,`removeAll`,`retainAll`and`clear`operations. It does not support the`add`or`addAll`operations. | Return || |------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------| | [MutableCollection](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-mutable-collection/index.html) | a collection view of the values contained in this map |