@nuzyly Yes, you are completely correct.

ArithmeticException is a subclass of RuntimeException. RuntimeException and Error are called unchecked in Java terminology, because they do not need to be declared in a throws clause of a method. That's because they are meant to represent programming problems, that client code cannot expect to recover from (see the documentation and this short article for the details).

So my question is: Why should one declare such an exception? You wouldn't generally declare NullPointerExceptions, would you? I think it would be more appropriate, to document this kind of exception in a doc comment: /** @throws ArithmeticException if the result overflows a long */

The intention is better readable that way, but a comment would suit it better, I'd say.

What do you mean?

Why declare an unchecked exception?