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Can we have optional parameter in Java?
Java now supports optionals in 1.8, I’m stuck with programming on android so I’m using nulls until I can refactor the code to use optional types. Default arguments can not be used in Java.
Should I use optional ofNullable?
If you use Optional. ofNullable(foobar) and the foobar happens to be null due to the bug, then your program will silently continue working incorrectly, which may be a bigger disaster. This way an error may occur much later and it would be much harder to understand at which point it went wrong.
Why should optional not be used in arguments?
Many web pages specify Optional should not be used as method arguments. With this in mind, I could use the following method signature and add a clear Javadoc comment to specify that the arguments may be null, hoping future maintainers will read the Javadoc and therefore always carry out null checks prior to using the arguments (solution 2):
Can a variadic function accept an optional argument?
The only exception is variadic functions (like printf ). Historically, the open (2) function from POSIX accepted in some cases an optional third argument (at the time it was defined – in the 1970s and 1980s -, the calling conventions practically pushed arguments on the call stack, so ignoring that argument was simple to implement).
When to use the optional method in Java?
Using the Optional.orElseThrow () method represents another elegant alternative to the isPresent ()-get () pair. Sometimes, when an Optional value is not present, all you want to do is to throw a java.util.NoSuchElementException exception. Starting with Java 10, this can be done via the orElseThrow () method without arguments.
When to use optional the way it is intended?
Optional is intended to provide a limited mechanism for library method return types where there needed to be a clear way to represent “no result,” and using null for such was overwhelmingly likely to cause errors. So, how to use Optional the way it was intended?