The
ifPresentOrElse(Consumer, Runnable) method of
java.util.Optional class helps us to perform the specified Consumer action the value of this Optional object. If a value is not present in this Optional, then this method performs the given empty-based Runnable emptyAction, passed as the second parameter
Syntax:
public void ifPresentOrElse(Consumer<T> action,
Runnable emptyAction)
Parameters: This method accepts two parameters:
- action: which is the action to be performed on this Optional, if a value is present.
- emptyAction: which is the empty-based action to be performed, if no value is present.
Return value: This method returns nothing.
Exception: This method throw
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.
Below programs illustrate ifPresentOrElse() method:
Note: As this method was added in Java 9, the programs need JDK 9 to execute.
Program 1:
Output:
Optional: Optional[9455]
Value is present, its: 9455
Program 2:
