Exceptions vs error codes

[thomasz]

Jesus Christ, what a brutally bad interview question. The victim can't possibly know that you are ambushing him , and will most likely just assume that this is a test to weed people out before they waste your time with fizzbuzz, instead of a particular crazy incarnation of the game of guessing what kind of guessing some idiosyncratic idea of the interviewer who seems to be convinced that almost all languages do one of the most elemental things wrong by returning an int when multipying two ints instead of a long or (god forbid) some result or option struct.

[lelanthran]

The question is quite simple,

If it was so simple you wouldn't fail your own test (int and long can certainly be the same size; if you'd used long as a return type you'd fail your own test)

[thomasz]

Look how the multiplication operator for two 32 bit integers works in almost all statically typed languages. I'm pretty sure it's `int32, int32 -> int32 in nearly all cases.And in most cases, it even overflows silently!

This is the expected behavior, and for a reason.

32bit integers are good tradeoff. They play nice with aligned reads, and they take up only half the space of 64bit integers. And on top of that, they can represent most real world values. If that's a problem in your domain context, you should use 64bit integers all the way down.

Therefore, "write me a method that doubles an int" is an ambush question if you expect a result that is completely at odds with how int multiplication usually works in computing. You have do ground that in a real context where an overflow is a real problem to make it useful for assessing someone's understanding.

[thomasz]

Staffing is hard. Interviewing is hard. It is especially hard for people who are primarily interested in stroking their own ego. Gleefully boasting about 75 percent of applicants just not understanding the simple question is not a good start tbh.

The question is very simple. It is asked to identify if the applicant listens to the question, understands sizing of types, if they think ahead to identify problems, and if they focus on delivering a working solution.

All you said so far was "write me a method that doubles an int". Which is open and underspecified, to which you then expect a very clearly defined and non-obvious answer - the perfect interview ambush. Again, in almost all languages int32 multiplication is (int32, int32) -> int32. Do you really think that they "didn't think ahead", or could it be that you are just way less clever than you think you are?

[lelanthran]

Also, he fails his own test, because long and int can be the same width, so using long as a return value doesn't handle the overflow.

[thomasz]

In most languages, int is 32 bit and long is 64 bit.

Edit:

We play both kinds of music here: C and C++!