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 |
Boolean |
Indicates whether some other object is "equal to" this |
Long |
If a value is present, returns the value, otherwise throws |
Int |
hashCode() Returns the hash code of the value, if present, otherwise |
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 |
Boolean |
If a value is present, returns |
static OptionalLong! |
Returns an |
Long |
If a value is present, returns the value, otherwise returns |
Long |
orElseGet(supplier: LongSupplier!) If a value is present, returns the value, otherwise returns the result produced by the supplying function. |
Long |
If a value is present, returns the value, otherwise throws |
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 |
String |
toString() Returns a non-empty string representation of this |
Public methods
empty
static fun empty(): OptionalLong!
Returns an empty OptionalLong
instance. No value is present for this OptionalLong
.
Return | |
---|---|
OptionalLong! |
an empty OptionalLong . |
equals
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
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
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
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
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
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
fun isPresent(): Boolean
If a value is present, returns true
, otherwise false
.
Return | |
---|---|
Boolean |
true if a value is present, otherwise false |
of
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
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
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
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
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
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
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 |