Return a value AND throw an exception?

Question

I'm working with an API that claims to return true if it succeeds, and false if it fails. But, it also claims to throw different exceptions if it fails. How can it return false and throw an exception?

Answer 1

It's not possible to both throw an exception and return a value from a single function call.

Perhaps it does something like returning false if there's an error, but throwing an exception if the input is invalid.

edit: PaulPRO posted a (now-deleted) answer pointing out that it is technically possible to cause an exception to be thrown in a different thread, while returning a value in the current one. I thought this was worth noting, even if it's not something you should ever see.

Answer 2

You can throw an exception that has a (in this case boolean) value:

public class ValueException extends Exception {     final boolean value;      public ValueException(boolean value, String message) {         super(message);         this.value = value;     }      public boolean getValue() {         return value;        } }