Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Summary: [Ctors](https://developer.android.com/reference/android/util/SparseBooleanArray#pubctors) \| [Methods](https://developer.android.com/reference/android/util/SparseBooleanArray#pubmethods) \| [Inherited Methods](https://developer.android.com/reference/android/util/SparseBooleanArray#inhmethods)

# SparseBooleanArray

*** ** * ** ***


`
public


class
SparseBooleanArray
`


`

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.SparseBooleanArray |

<br />

*** ** * ** ***

SparseBooleanArrays map integers to booleans.
Unlike a normal array of booleans
there can be gaps in the indices. It is intended to be more memory efficient
than using a HashMap to map Integers to Booleans, 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/SparseBooleanArray#keyAt(int)` and `https://developer.android.com/reference/android/util/SparseBooleanArray#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/SparseBooleanArray#SparseBooleanArray()() ` Creates a new SparseBooleanArray containing no mappings. |
| ` https://developer.android.com/reference/android/util/SparseBooleanArray#SparseBooleanArray(int)(int initialCapacity) ` Creates a new SparseBooleanArray 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/SparseBooleanArray#append(int,%20boolean)(int key, boolean 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/SparseBooleanArray#clear()() ` Removes all key-value mappings from this SparseBooleanArray. |
| ` https://developer.android.com/reference/android/util/SparseBooleanArray` | ` https://developer.android.com/reference/android/util/SparseBooleanArray#clone()() ` Creates and returns a copy of this object. |
| ` boolean` | ` https://developer.android.com/reference/android/util/SparseBooleanArray#compute(int,%20java.util.function.IntBinaryOperator)(int key, https://developer.android.com/reference/java/util/function/IntBinaryOperator function) ` Attempts to compute a new mapped value for the specified key based on its current mapped value (or false if there is no current mapping). |
| ` void` | ` https://developer.android.com/reference/android/util/SparseBooleanArray#delete(int)(int key) ` Removes the mapping from the specified key, if there was any. |
| ` boolean` | ` https://developer.android.com/reference/android/util/SparseBooleanArray#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object that) ` Indicates whether some other object is "equal to" this one. |
| ` boolean` | ` https://developer.android.com/reference/android/util/SparseBooleanArray#get(int)(int key) ` Gets the boolean mapped from the specified key, or `false` if no such mapping has been made. |
| ` boolean` | ` https://developer.android.com/reference/android/util/SparseBooleanArray#get(int,%20boolean)(int key, boolean valueIfKeyNotFound) ` Gets the boolean mapped from the specified key, or the specified value if no such mapping has been made. |
| ` int` | ` https://developer.android.com/reference/android/util/SparseBooleanArray#hashCode()() ` Returns a hash code value for the object. |
| ` int` | ` https://developer.android.com/reference/android/util/SparseBooleanArray#indexOfKey(int)(int key) ` Returns the index for which `https://developer.android.com/reference/android/util/SparseBooleanArray#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/SparseBooleanArray#indexOfValue(boolean)(boolean value) ` Returns an index for which `https://developer.android.com/reference/android/util/SparseBooleanArray#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/SparseBooleanArray#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 SparseBooleanArray stores. |
| ` void` | ` https://developer.android.com/reference/android/util/SparseBooleanArray#put(int,%20boolean)(int key, boolean 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/SparseBooleanArray#removeAt(int)(int index) ` Removes the mapping at the specified index. |
| ` void` | ` https://developer.android.com/reference/android/util/SparseBooleanArray#setValueAt(int,%20boolean)(int index, boolean value) ` Directly set the value at a particular index. |
| ` int` | ` https://developer.android.com/reference/android/util/SparseBooleanArray#size()() ` Returns the number of key-value mappings that this SparseBooleanArray currently stores. |
| ` https://developer.android.com/reference/java/lang/String` | ` https://developer.android.com/reference/android/util/SparseBooleanArray#toString()() ` Returns a string representation of the object. This implementation composes a string by iterating over its mappings. |
| ` boolean` | ` https://developer.android.com/reference/android/util/SparseBooleanArray#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 SparseBooleanArray 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

### SparseBooleanArray

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public SparseBooleanArray ()
```

Creates a new SparseBooleanArray containing no mappings.

<br />

### SparseBooleanArray

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public SparseBooleanArray (int initialCapacity)
```

Creates a new SparseBooleanArray 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 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public void append (int key, 
                boolean 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` | `boolean` <br /> |

### clear

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public void clear ()
```

Removes all key-value mappings from this SparseBooleanArray.

<br />

### clone

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public SparseBooleanArray 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/SparseBooleanArray` | a clone of this instance. <br /> |

### compute

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

```
public boolean compute (int key, 
                IntBinaryOperator function)
```

Attempts to compute a new mapped value for the specified key based on its current mapped
value (or false if there is no current mapping). The boolean values passed to and returned
from the function are converted to integers (0 for false and true otherwise) to avoid type
boxing.

<br />

| Parameters ||
|---|---|
| `key` | `int`: The key to compute the value for. <br /> |
| `function` | `IntBinaryOperator`: The function to compute the new value. For the second argument that represents the current mapped value, 0 is used for false and 1 for true. The returned value will be converted to a boolean similarly, 0 for false and true otherwise. This value cannot be `null`. <br /> |

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

### delete

Added in [API level 1](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 /> |

### equals

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public boolean equals (Object that)
```

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


The `equals` method implements an equivalence relation
on non-null object references:

- It is *reflexive*: for any non-null reference value `x`, `x.equals(x)` should return `true`.
- It is *symmetric*: for any non-null reference values `x` and `y`, `x.equals(y)` should return `true` if and only if `y.equals(x)` returns `true`.
- It is *transitive*: for any non-null reference values `x`, `y`, and `z`, if `x.equals(y)` returns `true` and `y.equals(z)` returns `true`, then `x.equals(z)` should return `true`.
- It is *consistent*: for any non-null reference values `x` and `y`, multiple invocations of `x.equals(y)` consistently return `true` or consistently return `false`, provided no information used in `equals` comparisons on the objects is modified.
- For any non-null reference value `x`, `x.equals(null)` should return `false`.


An equivalence relation partitions the elements it operates on
into *equivalence classes*; all the members of an
equivalence class are equal to each other. Members of an
equivalence class are substitutable for each other, at least
for some purposes.

<br />

| Parameters ||
|---|---|
| `that` | `Object`: This value may be `null`. <br /> |

| Returns ||
|---|---|
| `boolean` | `true` if this object is the same as the obj argument; `false` otherwise. <br /> |

### get

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public boolean get (int key)
```

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

<br />

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

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

### get

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

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

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

<br />

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

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

### hashCode

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public int hashCode ()
```

Returns a hash code value for the object. This method is
supported for the benefit of hash tables such as those provided by
`https://developer.android.com/reference/java/util/HashMap`.


The general contract of `hashCode` is:

- Whenever it is invoked on the same object more than once during an execution of a Java application, the `hashCode` method must consistently return the same integer, provided no information used in `equals` comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
- If two objects are equal according to the `https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object)` method, then calling the `hashCode` method on each of the two objects must produce the same integer result.
- It is *not* required that if two objects are unequal according to the `https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object)` method, then calling the `hashCode` method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

<br />

<br />

| Returns ||
|---|---|
| `int` | a hash code value for this object. <br /> |

### indexOfKey

Added in [API level 1](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/SparseBooleanArray#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 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public int indexOfValue (boolean value)
```

Returns an index for which `https://developer.android.com/reference/android/util/SparseBooleanArray#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` | `boolean` <br /> |

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

### keyAt

Added in [API level 1](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
SparseBooleanArray 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 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public void put (int key, 
                boolean 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` | `boolean` <br /> |

### removeAt

Added in [API level 28](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

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

Removes the mapping at the specified index.


For indices outside of the range `0...size()-1`, the behavior is undefined.

<br />

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

### setValueAt

Added in [API level 29](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public void setValueAt (int index, 
                boolean value)
```

Directly set the value at a particular index.

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 /> |
| `value` | `boolean` <br /> |

### size

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public int size ()
```

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

<br />

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

### toString

Added in [API level 1](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 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public boolean valueAt (int index)
```

Given an index in the range `0...size()-1`, returns
the value from the `index`th key-value mapping that this
SparseBooleanArray 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 ||
|---|---|
| `boolean` | <br /> |