A container object which may or may not contain a double
value.
If a value is present, isPresent()
will return true
and
getAsDouble()
will return the value.
Additional methods that depend on the presence or absence of a contained
value are provided, such as orElse()
(return a default value if value not present) and
ifPresent()
(execute a block
of code if the value is present).
Public Method Summary
static OptionalDouble |
empty()
Returns an empty
OptionalDouble instance. |
boolean |
equals(Object obj)
Indicates whether some other object is "equal to" this OptionalDouble.
|
double |
getAsDouble()
If a value is present in this
OptionalDouble , returns the value,
otherwise throws NoSuchElementException . |
int |
hashCode()
Returns the hash code value of the present value, if any, or 0 (zero) if
no value is present.
|
void |
ifPresent(DoubleConsumer consumer)
Have the specified consumer accept the value if a value is present,
otherwise do nothing.
|
boolean |
isPresent()
Return
true if there is a value present, otherwise false . |
static OptionalDouble |
of(double value)
Return an
OptionalDouble with the specified value present. |
double |
orElse(double other)
Return the value if present, otherwise return
other . |
double |
orElseGet(DoubleSupplier other)
Return the value if present, otherwise invoke
other and return
the result of that invocation. |
<X extends Throwable> double |
orElseThrow(Supplier<X> exceptionSupplier)
Return the contained value, if present, otherwise throw an exception
to be created by the provided supplier.
|
String |
toString()
Returns a non-empty string representation of this object suitable for
debugging.
|
Inherited Method Summary
Public Methods
public static OptionalDouble empty ()
Returns an empty OptionalDouble
instance. No value is present for this
OptionalDouble.
Returns
- an empty
OptionalDouble
.
public boolean equals (Object obj)
Indicates whether some other object is "equal to" this OptionalDouble. The other object is considered equal if:
- it is also an
OptionalDouble
and; - both instances have no value present or;
- the present values are "equal to" each other via
Double.compare() == 0
.
Parameters
obj | an object to be tested for equality |
---|
Returns
- {code true} if the other object is "equal to" this object
otherwise
false
public double getAsDouble ()
If a value is present in this OptionalDouble
, returns the value,
otherwise throws NoSuchElementException
.
Returns
- the value held by this
OptionalDouble
Throws
NoSuchElementException | if there is no value present |
---|
See Also
public int hashCode ()
Returns the hash code value of the present value, if any, or 0 (zero) if no value is present.
Returns
- hash code value of the present value or 0 if no value is present
public void ifPresent (DoubleConsumer consumer)
Have the specified consumer accept the value if a value is present, otherwise do nothing.
Parameters
consumer | block to be executed if a value is present |
---|
Throws
NullPointerException | if value is present and consumer is
null
|
---|
public boolean isPresent ()
Return true
if there is a value present, otherwise false
.
Returns
true
if there is a value present, otherwisefalse
public static OptionalDouble of (double value)
Return an OptionalDouble
with the specified value present.
Parameters
value | the value to be present |
---|
Returns
- an
OptionalDouble
with the value present
public double orElse (double other)
Return the value if present, otherwise return other
.
Parameters
other | the value to be returned if there is no value present |
---|
Returns
- the value, if present, otherwise
other
public double orElseGet (DoubleSupplier other)
Return the value if present, otherwise invoke other
and return
the result of that invocation.
Parameters
other | a DoubleSupplier whose result is returned if no value
is present |
---|
Returns
- the value if present otherwise the result of
other.getAsDouble()
Throws
NullPointerException | if value is not present and other is
null
|
---|
public double orElseThrow (Supplier<X> exceptionSupplier)
Return the contained value, if present, otherwise throw an exception to be created by the provided supplier.
Parameters
exceptionSupplier | The supplier which will return the exception to be thrown |
---|
Returns
- the present value
Throws
if there is no value present | |
NullPointerException | if no value is present and
exceptionSupplier is null
|
Throwable |
public String toString ()
Returns a non-empty string representation of this object suitable for debugging. The exact presentation format is unspecified and may vary between implementations and versions.
Returns
- the string representation of this instance