Added in API level 24

OptionalLong

class OptionalLong

kotlin.Any
↳	java.util.OptionalLong

A container object which may or may not contain a long value. If a value is present, isPresent() returns true. If no value is present, the object is considered empty and isPresent() returns false.

Additional methods that depend on the presence or absence of a contained value are provided, such as orElse() (returns a default value if no value is present) and ifPresent() (performs an action if a value is present).

This is a value-based class; programmers should treat instances that are equal as interchangeable and should not use instances for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail.

Summary

Public methods
static OptionalLong!	empty() Returns an empty OptionalLong instance.
Boolean	equals(other: Any?) Indicates whether some other object is "equal to" this OptionalLong.
Long	getAsLong() If a value is present, returns the value, otherwise throws NoSuchElementException.
Int	hashCode() Returns the hash code of the value, if present, otherwise 0 (zero) if no value is present.
Unit	ifPresent(action: LongConsumer!) If a value is present, performs the given action with the value, otherwise does nothing.
Unit	ifPresentOrElse(action: LongConsumer!, emptyAction: Runnable!) If a value is present, performs the given action with the value, otherwise performs the given empty-based action.
Boolean	isEmpty() If a value is not present, returns true, otherwise false.
Boolean	isPresent() If a value is present, returns true, otherwise false.
static OptionalLong!	of(value: Long) Returns an OptionalLong describing the given value.
Long	orElse(other: Long) If a value is present, returns the value, otherwise returns other.
Long	orElseGet(supplier: LongSupplier!) If a value is present, returns the value, otherwise returns the result produced by the supplying function.
Long	orElseThrow() If a value is present, returns the value, otherwise throws NoSuchElementException.
Long	orElseThrow(exceptionSupplier: Supplier<out X>!) If a value is present, returns the value, otherwise throws an exception produced by the exception supplying function.
LongStream!	stream() If a value is present, returns a sequential LongStream containing only that value, otherwise returns an empty LongStream.
String	toString() Returns a non-empty string representation of this OptionalLong suitable for debugging.

Public methods

empty

Added in API level 24

static fun empty(): OptionalLong!

Returns an empty OptionalLong instance. No value is present for this OptionalLong.

Return
OptionalLong!	an empty OptionalLong.

equals

Added in API level 24

fun equals(other: Any?): Boolean

Indicates whether some other object is "equal to" this OptionalLong. The other object is considered equal if:

• it is also an OptionalLong and;
• both instances have no value present or;
• the present values are "equal to" each other via ==.

Parameters
obj	an object to be tested for equality

Return
Boolean	true if the other object is "equal to" this object otherwise false

getAsLong

Added in API level 24

fun getAsLong(): Long

If a value is present, returns the value, otherwise throws NoSuchElementException.

Return
Long	the value described by this OptionalLong

Exceptions
java.util.NoSuchElementException	if no value is present

hashCode

Added in API level 24

fun hashCode(): Int

Returns the hash code of the value, if present, otherwise 0 (zero) if no value is present.

Return
Int	hash code value of the present value or 0 if no value is present

ifPresent

Added in API level 24

fun ifPresent(action: LongConsumer!): Unit

If a value is present, performs the given action with the value, otherwise does nothing.

Parameters
action	LongConsumer!: the action to be performed, if a value is present

Exceptions
java.lang.NullPointerException	if value is present and the given action is null

ifPresentOrElse

Added in API level 33

fun ifPresentOrElse(
    action: LongConsumer!, 
    emptyAction: Runnable!
): Unit

If a value is present, performs the given action with the value, otherwise performs the given empty-based action.

Parameters
action	LongConsumer!: the action to be performed, if a value is present
emptyAction	Runnable!: the empty-based action to be performed, if no value is present

Exceptions
java.lang.NullPointerException	if a value is present and the given action is null, or no value is present and the given empty-based action is null.

isEmpty

Added in API level 33

fun isEmpty(): Boolean

If a value is not present, returns true, otherwise false.

Return
Boolean	true if a value is not present, otherwise false

isPresent

Added in API level 24

fun isPresent(): Boolean

If a value is present, returns true, otherwise false.

Return
Boolean	true if a value is present, otherwise false

of

Added in API level 24

static fun of(value: Long): OptionalLong!

Returns an OptionalLong describing the given value.

Parameters
value	Long: the value to describe

Return
OptionalLong!	an OptionalLong with the value present

orElse

Added in API level 24

fun orElse(other: Long): Long

If a value is present, returns the value, otherwise returns other.

Parameters
other	Long: the value to be returned, if no value is present

Return
Long	the value, if present, otherwise other

orElseGet

Added in API level 24

fun orElseGet(supplier: LongSupplier!): Long

If a value is present, returns the value, otherwise returns the result produced by the supplying function.

Parameters
supplier	LongSupplier!: the supplying function that produces a value to be returned

Return
Long	the value, if present, otherwise the result produced by the supplying function

Exceptions
java.lang.NullPointerException	if no value is present and the supplying function is null

orElseThrow

Added in API level 33

fun orElseThrow(): Long

If a value is present, returns the value, otherwise throws NoSuchElementException.

Return
Long	the value described by this OptionalLong

Exceptions
java.util.NoSuchElementException	if no value is present

orElseThrow

Added in API level 24

fun <X : Throwable!> orElseThrow(exceptionSupplier: Supplier<out X>!): Long

If a value is present, returns the value, otherwise throws an exception produced by the exception supplying function.

Parameters
<X>	Type of the exception to be thrown
exceptionSupplier	Supplier<out X>!: the supplying function that produces an exception to be thrown

Return
Long	the value, if present

Exceptions
X	if no value is present
java.lang.NullPointerException	if no value is present and the exception supplying function is null

stream

Added in API level 33

fun stream(): LongStream!

If a value is present, returns a sequential LongStream containing only that value, otherwise returns an empty LongStream.

Return
LongStream!	the optional value as an LongStream

toString

Added in API level 24

fun toString(): String

Returns a non-empty string representation of this OptionalLong suitable for debugging. The exact presentation format is unspecified and may vary between implementations and versions.

Return
String	the string representation of this instance