Best practice when returning something from a routine.

Question

What’s the best practice when returning something from a routine? Should I return a status bit always or just on failure? For example:

Return(0, “Failed because….”) on failure,
Return(1, success_value, second_success_value) on success.

Or

Return(0, “Failed because….”) on failure,
Return( success_value, second_success_value) on success.

I usually program in Perl, but I guess the question stands for whatever language I might try to program in. Thanks!

Answer 1

In languages that support them, you should throw descriptive exceptions.

Where applicable, you should throw exceptions of the correct type (eg, ArgumentNullException or InvalidOperationException in .Net)

Answer 2

hey Akers, I've asked myself a similar question in the past...

Some of these answers might help you

http://stackoverflow.com/questions/973292/is-it-bad-practice-to-return-exceptions-from-your-methods

The basic conclusion I came to is to only return something, anything, if the caller requires it.

So, for the most part, I found its better to just make my method Void, and have it throw a meaningful exception if anything goes wrong. If everything goes ok, then I, as the caller, don't really care

Answer 3

The answer is very language dependent. You should follow the idiom for the language you are using. The idiom for Perl, which you mentioned, is to return zero(0) for success and other values for failure. If you need to return multiple values, as in your example, one of them could always be the success/failure code.

If you're using a language that supports exceptions (eg. Java, C#, C++) then you should indicate exceptional conditions (eg. failures) using an exception. If the routine completes normally (ie. no exceptions) then it can be assumed to have succeeded and any returned values can be used safely.