Added in API level 24

Summary: Methods | Inherited Methods

OptionalDouble

public final class OptionalDouble
extends Object

java.lang.Object
↳	java.util.OptionalDouble

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).

Summary

Public methods
`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 string representation of the object. Returns a non-empty string representation of this object suitable for debugging.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeout, int nanos)` Causes the current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed.
`final void`	`wait(long timeout)` Causes the current thread to wait until either another thread invokes the `notify()` method or the `notifyAll()` method for this object, or a specified amount of time has elapsed.
`final void`	`wait()` Causes the current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object.

Public methods

empty

Added in API level 24

public static OptionalDouble empty ()

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

API Note:

Though it may be tempting to do so, avoid testing if an object is empty by comparing with == against instances returned by Option.empty(). There is no guarantee that it is a singleton. Instead, use isPresent().

Returns
`OptionalDouble`	an empty `OptionalDouble`.

equals

Added in API level 24

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`	`Object`: an object to be tested for equality

Returns
`boolean`	{code true} if the other object is "equal to" this object otherwise `false`

getAsDouble

Added in API level 24

public double getAsDouble ()

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

Returns
`double`	the value held by this `OptionalDouble`

Throws
`NoSuchElementException`	if there is no value present

See also:

isPresent()

hashCode

Added in API level 24

public int hashCode ()

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

Returns
`int`	hash code value of the present value or 0 if no value is present

ifPresent

Added in API level 24

public void ifPresent (DoubleConsumer consumer)

Have the specified consumer accept the value if a value is present, otherwise do nothing.

Parameters
`consumer`	`DoubleConsumer`: block to be executed if a value is present

Throws
`NullPointerException`	if value is present and `consumer` is null

isPresent

Added in API level 24

public boolean isPresent ()

Return true if there is a value present, otherwise false.

Returns
`boolean`	`true` if there is a value present, otherwise `false`

of

Added in API level 24

public static OptionalDouble of (double value)

Return an OptionalDouble with the specified value present.

Parameters
`value`	`double`: the value to be present

Returns
`OptionalDouble`	an `OptionalDouble` with the value present

orElse

Added in API level 24

public double orElse (double other)

Return the value if present, otherwise return other.

Parameters
`other`	`double`: the value to be returned if there is no value present

Returns
`double`	the value, if present, otherwise `other`

orElseGet

Added in API level 24

public double orElseGet (DoubleSupplier other)

Return the value if present, otherwise invoke other and return the result of that invocation.

Parameters
`other`	`DoubleSupplier`: a `DoubleSupplier` whose result is returned if no value is present

Returns
`double`	the value if present otherwise the result of `other.getAsDouble()`

Throws
`NullPointerException`	if value is not present and `other` is null

orElseThrow

Added in API level 24

public double orElseThrow (Supplier<X> exceptionSupplier)

Return the contained value, if present, otherwise throw an exception to be created by the provided supplier.

API Note:

A method reference to the exception constructor with an empty argument list can be used as the supplier. For example, IllegalStateException::new

Parameters
`exceptionSupplier`	`Supplier`: The supplier which will return the exception to be thrown

Returns
`double`	the present value

Throws
	if there is no value present
`NullPointerException`	if no value is present and `exceptionSupplier` is null
`Throwable`

toString

Added in API level 24

public String toString ()

Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

 getClass().getName() + '@' + Integer.toHexString(hashCode())

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.

Implementation Requirements:

If a value is present the result must include its string representation in the result. Empty and present instances must be unambiguously differentiable.

Returns
`String`	the string representation of this instance