Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Summary: [Ctors](https://developer.android.com/reference/android/util/SparseLongArray#pubctors) \| [Methods](https://developer.android.com/reference/android/util/SparseLongArray#pubmethods) \| [Inherited Methods](https://developer.android.com/reference/android/util/SparseLongArray#inhmethods)

# SparseLongArray

*** ** * ** ***


`
public


class
SparseLongArray
`


`

extends https://developer.android.com/reference/java/lang/Object


`

`


implements

https://developer.android.com/reference/java/lang/Cloneable


`

|---|---|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) ||
| ↳ | android.util.SparseLongArray |

<br />

*** ** * ** ***

SparseLongArrays map integers to longs. Unlike a normal array of longs,
there can be gaps in the indices. It is intended to be more memory efficient
than using a HashMap to map Integers to Longs, both because it avoids
auto-boxing keys and values and its data structure doesn't rely on an extra entry object
for each mapping.

Note that this container keeps its mappings in an array data structure,
using a binary search to find keys. The implementation is not intended to be appropriate for
data structures
that may contain large numbers of items. It is generally slower than a traditional
HashMap, since lookups require a binary search and adds and removes require inserting
and deleting entries in the array. For containers holding up to hundreds of items,
the performance difference is not significant, less than 50%.

It is possible to iterate over the items in this container using
`https://developer.android.com/reference/android/util/SparseLongArray#keyAt(int)` and `https://developer.android.com/reference/android/util/SparseLongArray#valueAt(int)`. Iterating over the keys using
`keyAt(int)` with ascending values of the index will return the
keys in ascending order, or the values corresponding to the keys in ascending
order in the case of `valueAt(int)`.

<br />

## Summary

| ### Public constructors ||
|---|---|
| ` https://developer.android.com/reference/android/util/SparseLongArray#SparseLongArray()() ` Creates a new SparseLongArray containing no mappings. |
| ` https://developer.android.com/reference/android/util/SparseLongArray#SparseLongArray(int)(int initialCapacity) ` Creates a new SparseLongArray containing no mappings that will not require any additional memory allocation to store the specified number of mappings. |

| ### Public methods ||
|---|---|
| ` void` | ` https://developer.android.com/reference/android/util/SparseLongArray#append(int,%20long)(int key, long value) ` Puts a key/value pair into the array, optimizing for the case where the key is greater than all existing keys in the array. |
| ` void` | ` https://developer.android.com/reference/android/util/SparseLongArray#clear()() ` Removes all key-value mappings from this SparseLongArray. |
| ` https://developer.android.com/reference/android/util/SparseLongArray` | ` https://developer.android.com/reference/android/util/SparseLongArray#clone()() ` Creates and returns a copy of this object. |
| ` long` | ` https://developer.android.com/reference/android/util/SparseLongArray#compute(int,%20java.util.function.LongBinaryOperator)(int key, https://developer.android.com/reference/java/util/function/LongBinaryOperator function) ` Attempts to compute a new mapped value for the specified key based on its current mapped value (or 0 if there is no current mapping). |
| ` void` | ` https://developer.android.com/reference/android/util/SparseLongArray#delete(int)(int key) ` Removes the mapping from the specified key, if there was any. |
| ` long` | ` https://developer.android.com/reference/android/util/SparseLongArray#get(int)(int key) ` Gets the long mapped from the specified key, or `0` if no such mapping has been made. |
| ` long` | ` https://developer.android.com/reference/android/util/SparseLongArray#get(int,%20long)(int key, long valueIfKeyNotFound) ` Gets the long mapped from the specified key, or the specified value if no such mapping has been made. |
| ` int` | ` https://developer.android.com/reference/android/util/SparseLongArray#indexOfKey(int)(int key) ` Returns the index for which `https://developer.android.com/reference/android/util/SparseLongArray#keyAt(int)` would return the specified key, or a negative number if the specified key is not mapped. |
| ` int` | ` https://developer.android.com/reference/android/util/SparseLongArray#indexOfValue(long)(long value) ` Returns an index for which `https://developer.android.com/reference/android/util/SparseLongArray#valueAt(int)` would return the specified key, or a negative number if no keys map to the specified value. |
| ` int` | ` https://developer.android.com/reference/android/util/SparseLongArray#keyAt(int)(int index) ` Given an index in the range `0...size()-1`, returns the key from the `index`th key-value mapping that this SparseLongArray stores. |
| ` void` | ` https://developer.android.com/reference/android/util/SparseLongArray#put(int,%20long)(int key, long value) ` Adds a mapping from the specified key to the specified value, replacing the previous mapping from the specified key if there was one. |
| ` void` | ` https://developer.android.com/reference/android/util/SparseLongArray#removeAt(int)(int index) ` Removes the mapping at the given index. |
| ` int` | ` https://developer.android.com/reference/android/util/SparseLongArray#size()() ` Returns the number of key-value mappings that this SparseLongArray currently stores. |
| ` https://developer.android.com/reference/java/lang/String` | ` https://developer.android.com/reference/android/util/SparseLongArray#toString()() ` Returns a string representation of the object. This implementation composes a string by iterating over its mappings. |
| ` long` | ` https://developer.android.com/reference/android/util/SparseLongArray#valueAt(int)(int index) ` Given an index in the range `0...size()-1`, returns the value from the `index`th key-value mapping that this SparseLongArray stores. |

### Inherited methods

From class `

https://developer.android.com/reference/java/lang/Object

` `


https://developer.android.com/reference/java/lang/Object` `
https://developer.android.com/reference/java/lang/Object#clone()()
`

Creates and returns a copy of this object.


`


boolean` `
https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object obj)
`

Indicates whether some other object is "equal to" this one.


`


void` `
https://developer.android.com/reference/java/lang/Object#finalize()()
`

Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.


`


final

https://developer.android.com/reference/java/lang/Class<?>` `
https://developer.android.com/reference/java/lang/Object#getClass()()
`

Returns the runtime class of this `Object`.


`


int` `
https://developer.android.com/reference/java/lang/Object#hashCode()()
`

Returns a hash code value for the object.


`


final

void` `
https://developer.android.com/reference/java/lang/Object#notify()()
`

Wakes up a single thread that is waiting on this object's
monitor.


`


final

void` `
https://developer.android.com/reference/java/lang/Object#notifyAll()()
`

Wakes up all threads that are waiting on this object's monitor.


`


https://developer.android.com/reference/java/lang/String` `
https://developer.android.com/reference/java/lang/Object#toString()()
`

Returns a string representation of the object.


`


final

void` `
https://developer.android.com/reference/java/lang/Object#wait(long,%20int)(long timeoutMillis, int nanos)
`

Causes the current thread to wait until it is awakened, typically
by being *notified* or *interrupted*, or until a
certain amount of real time has elapsed.


`


final

void` `
https://developer.android.com/reference/java/lang/Object#wait(long)(long timeoutMillis)
`

Causes the current thread to wait until it is awakened, typically
by being *notified* or *interrupted*, or until a
certain amount of real time has elapsed.


`


final

void` `
https://developer.android.com/reference/java/lang/Object#wait()()
`

Causes the current thread to wait until it is awakened, typically
by being *notified* or *interrupted*.


## Public constructors

### SparseLongArray

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public SparseLongArray ()
```

Creates a new SparseLongArray containing no mappings.

<br />

### SparseLongArray

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public SparseLongArray (int initialCapacity)
```

Creates a new SparseLongArray containing no mappings that will not
require any additional memory allocation to store the specified
number of mappings. If you supply an initial capacity of 0, the
sparse array will be initialized with a light-weight representation
not requiring any additional array allocations.

<br />

| Parameters ||
|---|---|
| `initialCapacity` | `int` <br /> |

## Public methods

### append

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public void append (int key, 
                long value)
```

Puts a key/value pair into the array, optimizing for the case where
the key is greater than all existing keys in the array.

<br />

| Parameters ||
|---|---|
| `key` | `int` <br /> |
| `value` | `long` <br /> |

### clear

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public void clear ()
```

Removes all key-value mappings from this SparseLongArray.

<br />

### clone

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public SparseLongArray clone ()
```

Creates and returns a copy of this object. The precise meaning
of "copy" may depend on the class of the object. The general
intent is that, for any object `x`, the expression:
>
> ```
> x.clone() != x
> ```
will be true, and that the expression:
>
> ```
> x.clone().getClass() == x.getClass()
> ```
will be `true`, but these are not absolute requirements. While it is typically the case that:
>
> ```
> x.clone().equals(x)
> ```
will be `true`, this is not an absolute requirement.


By convention, the returned object should be obtained by calling
`super.clone`. If a class and all of its superclasses (except
`Object`) obey this convention, it will be the case that
`x.clone().getClass() == x.getClass()`.


By convention, the object returned by this method should be independent
of this object (which is being cloned). To achieve this independence,
it may be necessary to modify one or more fields of the object returned
by `super.clone` before returning it. Typically, this means
copying any mutable objects that comprise the internal "deep structure"
of the object being cloned and replacing the references to these
objects with references to the copies. If a class contains only
primitive fields or references to immutable objects, then it is usually
the case that no fields in the object returned by `super.clone`
need to be modified.

<br />

| Returns ||
|---|---|
| `https://developer.android.com/reference/android/util/SparseLongArray` | a clone of this instance. <br /> |

### compute

Added in [version 37.2](https://developer.android.com/topic/libraries/support-library/revisions)

```
public long compute (int key, 
                LongBinaryOperator function)
```

Attempts to compute a new mapped value for the specified key based on its current mapped
value (or 0 if there is no current mapping).

<br />

| Parameters ||
|---|---|
| `key` | `int`: The key to compute the value for. <br /> |
| `function` | `LongBinaryOperator`: The function to compute the new value. This value cannot be `null`. <br /> |

| Returns ||
|---|---|
| `long` | The new mapped value. <br /> |

### delete

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public void delete (int key)
```

Removes the mapping from the specified key, if there was any.

<br />

| Parameters ||
|---|---|
| `key` | `int` <br /> |

### get

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public long get (int key)
```

Gets the long mapped from the specified key, or `0`
if no such mapping has been made.

<br />

| Parameters ||
|---|---|
| `key` | `int` <br /> |

| Returns ||
|---|---|
| `long` | <br /> |

### get

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public long get (int key, 
                long valueIfKeyNotFound)
```

Gets the long mapped from the specified key, or the specified value
if no such mapping has been made.

<br />

| Parameters ||
|---|---|
| `key` | `int` <br /> |
| `valueIfKeyNotFound` | `long` <br /> |

| Returns ||
|---|---|
| `long` | <br /> |

### indexOfKey

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public int indexOfKey (int key)
```

Returns the index for which `https://developer.android.com/reference/android/util/SparseLongArray#keyAt(int)` would return the
specified key, or a negative number if the specified
key is not mapped.

<br />

| Parameters ||
|---|---|
| `key` | `int` <br /> |

| Returns ||
|---|---|
| `int` | <br /> |

### indexOfValue

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public int indexOfValue (long value)
```

Returns an index for which `https://developer.android.com/reference/android/util/SparseLongArray#valueAt(int)` would return the
specified key, or a negative number if no keys map to the
specified value.
Beware that this is a linear search, unlike lookups by key,
and that multiple keys can map to the same value and this will
find only one of them.

<br />

| Parameters ||
|---|---|
| `value` | `long` <br /> |

| Returns ||
|---|---|
| `int` | <br /> |

### keyAt

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public int keyAt (int index)
```

Given an index in the range `0...size()-1`, returns
the key from the `index`th key-value mapping that this
SparseLongArray stores.

The keys corresponding to indices in ascending order are guaranteed to
be in ascending order, e.g., `keyAt(0)` will return the
smallest key and `keyAt(size()-1)` will return the largest
key.

For indices outside of the range `0...size()-1`, the behavior is undefined for
apps targeting `https://developer.android.com/reference/android/os/Build.VERSION_CODES#P` and earlier, and an
`https://developer.android.com/reference/java/lang/ArrayIndexOutOfBoundsException` is thrown for apps targeting
`https://developer.android.com/reference/android/os/Build.VERSION_CODES#Q` and later.

<br />

<br />

| Parameters ||
|---|---|
| `index` | `int` <br /> |

| Returns ||
|---|---|
| `int` | <br /> |

### put

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public void put (int key, 
                long value)
```

Adds a mapping from the specified key to the specified value,
replacing the previous mapping from the specified key if there
was one.

<br />

| Parameters ||
|---|---|
| `key` | `int` <br /> |
| `value` | `long` <br /> |

### removeAt

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public void removeAt (int index)
```

Removes the mapping at the given index.

<br />

| Parameters ||
|---|---|
| `index` | `int` <br /> |

### size

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public int size ()
```

Returns the number of key-value mappings that this SparseLongArray
currently stores.

<br />

| Returns ||
|---|---|
| `int` | <br /> |

### toString

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public String toString ()
```

Returns a string representation of the object.

This implementation composes a string by iterating over its mappings.

<br />

| Returns ||
|---|---|
| `https://developer.android.com/reference/java/lang/String` | a string representation of the object. <br /> |

### valueAt

Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public long valueAt (int index)
```

Given an index in the range `0...size()-1`, returns
the value from the `index`th key-value mapping that this
SparseLongArray stores.

The values corresponding to indices in ascending order are guaranteed
to be associated with keys in ascending order, e.g.,
`valueAt(0)` will return the value associated with the
smallest key and `valueAt(size()-1)` will return the value
associated with the largest key.

For indices outside of the range `0...size()-1`, the behavior is undefined for
apps targeting `https://developer.android.com/reference/android/os/Build.VERSION_CODES#P` and earlier, and an
`https://developer.android.com/reference/java/lang/ArrayIndexOutOfBoundsException` is thrown for apps targeting
`https://developer.android.com/reference/android/os/Build.VERSION_CODES#Q` and later.

<br />

<br />

| Parameters ||
|---|---|
| `index` | `int` <br /> |

| Returns ||
|---|---|
| `long` | <br /> |