OptionalInt

AI-generated Key Takeaways

• OptionalInt is a container that may or may not hold an integer value, providing methods to handle the presence or absence of the value.

• It offers methods like isPresent() to check for value presence, getAsInt() to retrieve the value if present, and orElse() to provide a default if absent.

• Methods such as ifPresent() allow executing code conditionally based on value presence, while orElseGet() and orElseThrow() offer more advanced handling of absent values.

• OptionalInt helps avoid null checks and potential NullPointerExceptions by encapsulating the possibility of a missing integer value.

public final class OptionalInt extends Object

A container object which may or may not contain a int value. If a value is present, isPresent() will return true and getAsInt() 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 OptionalInt	empty() Returns an empty OptionalInt instance.
boolean	equals(Object obj) Indicates whether some other object is "equal to" this OptionalInt.
int	getAsInt() If a value is present in this OptionalInt, 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(IntConsumer 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 OptionalInt	of(int value) Return an OptionalInt with the specified value present.
int	orElse(int other) Return the value if present, otherwise return other.
int	orElseGet(IntSupplier other) Return the value if present, otherwise invoke other and return the result of that invocation.
<X extends Throwable> int	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 containing a concise, human-readable description of this object. Returns a non-empty string representation of this object suitable for debugging.

Inherited Method Summary

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Public Methods

public static OptionalInt empty ()

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

Returns

• an empty OptionalInt

public boolean equals (Object obj)

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

• it is also an OptionalInt 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

Returns

• {code true} if the other object is "equal to" this object otherwise false

public int getAsInt ()

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

Returns

• the value held by this OptionalInt

Throws

NoSuchElementException	if there is no value present

See Also

• isPresent()

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 (IntConsumer 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, otherwise false

public static OptionalInt of (int value)

Return an OptionalInt with the specified value present.

Parameters

value	the value to be present

Returns

• an OptionalInt with the value present

public int orElse (int 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 int orElseGet (IntSupplier other)

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

Parameters

other	a IntSupplier whose result is returned if no value is present

Returns

• the value if present otherwise the result of other.getAsInt()

Throws

NullPointerException	if value is not present and other is null

public int 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 string containing a concise, human-readable description of this object. Subclasses are encouraged to override this method and provide an implementation that takes into account the object's type and data. The default implementation is equivalent to the following expression:

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

See Writing a useful toString method if you intend implementing your own toString method. 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