[toolslive]

The heuristic is that if the case is more frequent than something like 1/1000 then you don't use exceptions in these languages (C++, Java, ...). As they are a lot cheaper in languages like ML, people there tend to use them more for early exits out of things like folds.

A simple example:

  let prod = List.fold_left (fun acc a -> acc * a) 1.0 xs

should not fold over the whole list if a factor is 0.0 so they tend to use exceptions for that (or delimited continuations)

[kyllo]

Java doesn't really give you a choice though, because so many of the standard library classes have exceptions baked in. Any code you write related to file I/O for example will have to have either a "throws" or a "try/catch" on it, or else it won't even compile.

[judk]

Checked exceptions are much closer to "error codes" than unchecked exceptions. Checked exceptions just loosen the constraint a bit and let you defer handling to anywhere the caller's remaining function scope (or explicitly continue the throw)