SimpleArrayMap
Known direct subclasses
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 androidx.collection.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 preferable since it doesn't bring in any of the implementation of those APIs, allowing that code to be stripped by ProGuard.

NOTE: Consider using MutableScatterMap instead of this class. MutableScatterMap also avoids creating a new object per entry but offers better performance characteristics. If a Map interface is required, see MutableScatterMap.asMap. If a MutableMap interface is required, see MutableScatterMap.asMutableMap. A MutableScatterMap can also be passed as a ScatterMap to provide a read-only API surface.

Summary

Public constructors
<K : Any?, V : Any?> SimpleArrayMap(capacity: Int)

Create a new SimpleArrayMap with a given initial capacity.
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<K : Any?, V : Any?> SimpleArrayMap(map: SimpleArrayMap<K, V>?)

Create a new SimpleArrayMap with the mappings from the given map.
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Public functions
open Unit

Make the array map empty.
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open Boolean
containsKey(key: K)

Check whether a key exists in the array.
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open Boolean
containsValue(value: V)

Check whether a value exists in the array.
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open Unit
ensureCapacity(minimumCapacity: Int)

Ensure the array map can hold at least minimumCapacity items.
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open operator Boolean
equals(other: Any?)

This implementation returns false if the object is not a Map or SimpleArrayMap, or if the maps have different sizes.
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open operator V?
get(key: K)

Retrieve a value from the array.
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open V
getOrDefault(key: Any?, defaultValue: V)

Retrieve a value from the array, or defaultValue if there is no mapping for the key.
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open Int
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open Int
indexOfKey(key: K)

Returns the index of a key in the set.
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open Boolean

Return true if the array map contains no items.
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open K
keyAt(index: Int)

Return the key at the given index in the array.
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open V?
put(key: K, value: V)

Add a new value to the array map.
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open Unit
putAll(map: SimpleArrayMap<K, V>)

Perform a put of all key/value pairs in map
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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.
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open V?
remove(key: K)

Remove an existing key from the array map.
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open Boolean
remove(key: K, value: V)

Remove an existing key from the array map only if it is currently mapped to value.
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open V
removeAt(index: Int)

Remove the key/value mapping at the given index.
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open V?
replace(key: K, value: V)

Replace the mapping for key only if it is already mapped to a value.
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open Boolean
replace(key: K, oldValue: V, newValue: V)

Replace the mapping for key only if it is already mapped to oldValue.
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open V
setValueAt(index: Int, value: V)

Set the value at a given index in the array.
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open Int

Return the number of items in this array map.
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open String

Returns a string representation of the object.
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open V
valueAt(index: Int)

Return the value at the given index in the array.
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Public constructors

SimpleArrayMap

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<K : Any?, V : Any?> SimpleArrayMap(capacity: Int = 0)

Create a new SimpleArrayMap with a given initial capacity. The default capacity of an array map is 0, and will grow once items are added to it.

SimpleArrayMap

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<K : Any?, V : Any?> SimpleArrayMap(map: SimpleArrayMap<K, V>?)

Create a new SimpleArrayMap with the mappings from the given map.

Public functions

clear

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Added in 1.0.0
open fun clear(): Unit

Make the array map empty. All storage is released.

Throws
kotlin.ConcurrentModificationException

if it was detected that this SimpleArrayMap was written to while this operation was running.

containsKey

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Added in 1.3.0
open fun containsKey(key: K): Boolean

Check whether a key exists in the array.

Parameters
key: K

The key to search for.
Returns
Boolean

Returns true if the key exists, else false.

containsValue

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Added in 1.3.0
open fun containsValue(value: V): Boolean

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

Parameters
value: V

The value to search for.
Returns
Boolean

Returns true if the value exists, else false.

ensureCapacity

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Added in 1.0.0
open fun ensureCapacity(minimumCapacity: Int): Unit

Ensure the array map can hold at least minimumCapacity items.

Throws
kotlin.ConcurrentModificationException

if it was detected that this SimpleArrayMap was written to while this operation was running.

equals

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open operator 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

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Added in 1.3.0
open operator fun get(key: K): V?

Retrieve a value from the array.

Parameters
key: K

The key of the value to retrieve.
Returns
V?

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

getOrDefault

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Added in 1.1.0
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
Returns
V

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

hashCode

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open fun hashCode(): Int

indexOfKey

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Added in 1.3.0
open fun indexOfKey(key: K): Int

Returns the index of a key in the set.

Parameters
key: K

The key to search for.
Returns
Int

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

isEmpty

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Added in 1.0.0
open fun isEmpty(): Boolean

Return true if the array map contains no items.

keyAt

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Added in 1.0.0
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 (inclusive).
Returns
K

Returns the key stored at the given index.
Throws
kotlin.IllegalArgumentException

if index is not between 0 and size-1

put

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Added in 1.0.0
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. If this key already exists in the array, its value will be replaced.
value: V

The value to store for the given key.
Returns
V?

Returns the old value that was stored for the given key, or null if there was no such key.
Throws
kotlin.ConcurrentModificationException

if it was detected that this SimpleArrayMap was written to while this operation was running.

putAll

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Added in 1.0.0
open fun putAll(map: SimpleArrayMap<K, V>): Unit

Perform a put of all key/value pairs in map

Parameters
map: SimpleArrayMap<K, V>

The array whose contents are to be retrieved.

putIfAbsent

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Added in 1.1.0
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.
Returns
V?

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

remove

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Added in 1.3.0
open fun remove(key: K): V?

Remove an existing key from the array map.

Parameters
key: K

The key of the mapping to remove.
Returns
V?

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

remove

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Added in 1.3.0
open fun remove(key: K, value: V): Boolean

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

Parameters
key: K

The key of the mapping to remove.
value: V

The value expected to be mapped to the key.
Returns
Boolean

Returns true if the mapping was removed.

removeAt

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Added in 1.0.0
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 (inclusive).
Returns
V

Returns the value that was stored at this index.
Throws
kotlin.ConcurrentModificationException

if it was detected that this SimpleArrayMap was written to while this operation was running.
kotlin.IllegalArgumentException

if index is not between 0 and size-1

replace

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Added in 1.1.0
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.
Returns
V?

Returns the previous mapped value or null.

replace

Cmn
Added in 1.1.0
open fun replace(key: K, oldValue: V, newValue: V): Boolean

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

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.
Returns
Boolean

Returns true if the value was replaced.

setValueAt

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Added in 1.0.0
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 (inclusive).
value: V

The new value to store at this index.
Returns
V

Returns the previous value at the given index.
Throws
kotlin.IllegalArgumentException

if index is not between 0 and size-1

size

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Added in 1.0.0
open fun size(): Int

Return the number of items in this array map.

toString

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open fun toString(): String

Returns a string representation of the object.

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

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Added in 1.0.0
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 (inclusive).
Returns
V

Returns the value stored at the given index.
Throws
kotlin.IllegalArgumentException

if index is not between 0 and size-1