SimpleArrayMap

Kotlin |Java

open class SimpleArrayMap<K : Any!, V : Any!>

kotlin.Any
↳	androidx.collection.SimpleArrayMap

Known Direct Subclasses ArrayMap ArrayMap ArrayMap is a generic key->value mapping data structure that is designed to be more memory efficient than a traditional java.util.HashMap, this implementation is a version of the platform's android.util.ArrayMap that can be used on older versions of the platform.

Base implementation of ArrayMap that doesn't include any standard Java container API interoperability. These features are generally heavier-weight ways to interact with the container, so discouraged, but they can be useful to make it easier to use as a drop-in replacement for HashMap. If you don't need them, this class can be preferrable since it doesn't bring in any of the implementation of those APIs, allowing that code to be stripped by ProGuard.

Summary

Public constructors
<init>() Create a new empty ArrayMap.
<init>(capacity: Int) Create a new ArrayMap with a given initial capacity.
<init>(map: SimpleArrayMap<K, V>!) Create a new ArrayMap with the mappings from the given ArrayMap.

Public methods
open Unit	clear() Make the array map empty.
open Boolean	containsKey(@Nullable key: Any?) Check whether a key exists in the array.
open Boolean	containsValue(value: Any!) Check whether a value exists in the array.
open Unit	ensureCapacity(minimumCapacity: Int) Ensure the array map can hold at least minimumCapacity items.
open Boolean	equals(other: Any?) This implementation returns false if the object is not a Map or SimpleArrayMap, or if the maps have different sizes.
open V?	get(key: Any!) Retrieve a value from the array.
open V	getOrDefault(key: Any!, defaultValue: V) Retrieve a value from the array, or defaultValue if there is no mapping for the key.
open Int	hashCode()
open Int	indexOfKey(@Nullable key: Any?) Returns the index of a key in the set.
open Boolean	isEmpty() Return true if the array map contains no items.
open K	keyAt(index: Int) Return the key at the given index in the array.
open V?	put(key: K, value: V) Add a new value to the array map.
open Unit	putAll(@NonNull array: SimpleArrayMap<out K, out V>) Perform a put(Object, Object) of all key/value pairs in array
open V?	putIfAbsent(key: K, value: V) Add a new value to the array map only if the key does not already have a value or it is mapped to null.
open V?	remove(key: Any!) Remove an existing key from the array map.
open Boolean	remove(key: Any!, value: Any!) Remove an existing key from the array map only if it is currently mapped to value.
open V	removeAt(index: Int) Remove the key/value mapping at the given index.
open V?	replace(key: K, value: V) Replace the mapping for key only if it is already mapped to a value.
open Boolean	replace(key: K, oldValue: V, newValue: V) Replace the mapping for key only if it is already mapped to a value.
open V	setValueAt(index: Int, value: V) Set the value at a given index in the array.
open Int	size() Return the number of items in this array map.
open String	toString() This implementation composes a string by iterating over its mappings.
open V	valueAt(index: Int) Return the value at the given index in the array.

Public constructors

<init>

SimpleArrayMap()

Create a new empty ArrayMap. The default capacity of an array map is 0, and will grow once items are added to it.

<init>

SimpleArrayMap(capacity: Int)

Create a new ArrayMap with a given initial capacity.

<init>

SimpleArrayMap(map: SimpleArrayMap<K, V>!)

Create a new ArrayMap with the mappings from the given ArrayMap.

Public methods

clear

open fun clear(): Unit

Make the array map empty. All storage is released.

containsKey

open fun containsKey(@Nullable key: Any?): Boolean

Check whether a key exists in the array.

Parameters
key	Any?: The key to search for.

Return
Boolean	Returns true if the key exists, else false.

containsValue

open fun containsValue(value: Any!): Boolean

Check whether a value exists in the array. This requires a linear search through the entire array.

Parameters
value	Any!: The value to search for.

Return
Boolean	Returns true if the value exists, else false.

ensureCapacity

open fun ensureCapacity(minimumCapacity: Int): Unit

Ensure the array map can hold at least minimumCapacity items.

equals

open fun equals(other: Any?): Boolean

This implementation returns false if the object is not a Map or SimpleArrayMap, or if the maps have different sizes. Otherwise, for each key in this map, values of both maps are compared. If the values for any key are not equal, the method returns false, otherwise it returns true.

get

@Nullable open fun get(key: Any!): V?

Retrieve a value from the array.

Parameters
key	Any!: The key of the value to retrieve.

Return
V?	Returns the value associated with the given key, or null if there is no such key.

getOrDefault

open fun getOrDefault(
    key: Any!, 
    defaultValue: V
): V

Retrieve a value from the array, or defaultValue if there is no mapping for the key.

Parameters
key	Any!: The key of the value to retrieve.
defaultValue	V: The default mapping of the key

Return
V	Returns the value associated with the given key, or defaultValue if there is no mapping for the key.

hashCode

open fun hashCode(): Int

indexOfKey

open fun indexOfKey(@Nullable key: Any?): Int

Returns the index of a key in the set.

Parameters
key	Any?: The key to search for.

Return
Int	Returns the index of the key if it exists, else a negative integer.

isEmpty

open fun isEmpty(): Boolean

Return true if the array map contains no items.

keyAt

open fun keyAt(index: Int): K

Return the key at the given index in the array.

Parameters
index	Int: The desired index, must be between 0 and size()-1.

Return
K	Returns the key stored at the given index.

put

@Nullable open fun put(
    key: K, 
    value: V
): V?

Add a new value to the array map.

Parameters
key	K: The key under which to store the value. Must not be null. If this key already exists in the array, its value will be replaced.
value	V: The value to store for the given key.

Return
V?	Returns the old value that was stored for the given key, or null if there was no such key.

putAll

open fun putAll(@NonNull array: SimpleArrayMap<out K, out V>): Unit

Perform a put(Object, Object) of all key/value pairs in array

Parameters
array	SimpleArrayMap<out K, out V>: The array whose contents are to be retrieved.

putIfAbsent

@Nullable open fun putIfAbsent(
    key: K, 
    value: V
): V?

Add a new value to the array map only if the key does not already have a value or it is mapped to null.

Parameters
key	K: The key under which to store the value.
value	V: The value to store for the given key.

Return
V?	Returns the value that was stored for the given key, or null if there was no such key.

remove

@Nullable open fun remove(key: Any!): V?

Remove an existing key from the array map.

Parameters
key	Any!: The key of the mapping to remove.

Return
V?	Returns the value that was stored under the key, or null if there was no such key.

remove

open fun remove(
    key: Any!, 
    value: Any!
): Boolean

Remove an existing key from the array map only if it is currently mapped to value.

Parameters
key	Any!: The key of the mapping to remove.
value	Any!: The value expected to be mapped to the key.

Return
Boolean	Returns true if the mapping was removed.

removeAt

open fun removeAt(index: Int): V

Remove the key/value mapping at the given index.

Parameters
index	Int: The desired index, must be between 0 and size()-1.

Return
V	Returns the value that was stored at this index.

replace

@Nullable open fun replace(
    key: K, 
    value: V
): V?

Replace the mapping for key only if it is already mapped to a value.

Parameters
key	K: The key of the mapping to replace.
value	V: The value to store for the given key.

Return
V?	Returns the previous mapped value or null.

replace

open fun replace(
    key: K, 
    oldValue: V, 
    newValue: V
): Boolean

Replace the mapping for key only if it is already mapped to a value.

Parameters
key	K: The key of the mapping to replace.
oldValue	V: The value expected to be mapped to the key.
newValue	V: The value to store for the given key.

Return
Boolean	Returns true if the value was replaced.

setValueAt

open fun setValueAt(
    index: Int, 
    value: V
): V

Set the value at a given index in the array.

Parameters
index	Int: The desired index, must be between 0 and size()-1.
value	V: The new value to store at this index.

Return
V	Returns the previous value at the given index.

size

open fun size(): Int

Return the number of items in this array map.

toString

open fun toString(): String

This implementation composes a string by iterating over its mappings. If this map contains itself as a key or a value, the string "(this Map)" will appear in its place.

valueAt

open fun valueAt(index: Int): V

Return the value at the given index in the array.

Parameters
index	Int: The desired index, must be between 0 and size()-1.

Return
V	Returns the value stored at the given index.