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Comment by xrange | Hacker News Reader

>Pretty much everyone I asked to do Fizzbuzz failed

…I can't help but wonder what that really means? They gave up without producing any work? The program didn’t compile because they were typing random characters into the IDE? They were unfamiliar with the IDE, and couldn’t find the "compile" button? They couldn’t get the program to compile because of missing semicolons? The program didn’t write anything out to the terminal? The program never printed out "Fizz"? They printed out "FizzBuzz" on every line? The program never printed out numbers? The program printed out commas instead of newlines after every number? They went from 1 to 101 instead of 1 to 100?

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I once gave a Fizzbuzz-style question to a candidate, handed him a sheet of paper and a pen, and he writes down nothing and simply says "I'd use machine learning to do it."

...yeah, good idea, bro.

LOL

>I can't help but wonder what that really means?

My guess: it's the unfamiliarity of the mathematical modulus operator that trips most people up. A lot of CRUD developers will never need to use modulus calculations in day-to-day work. Pull some values from a database record, throw it up on a form, then save it back. Use plus+ for totaling dollar amounts. Use multiply* for calculating sales tax. A LOB programmer can do stuff like that for years without modulus% anywhere in his code. Something like credit-card number validation does use modulus calc but programmers can just copypaste[1] someone else's example or just use a library.

However, a lot of these FizzBuzz discussions talk about computer science graduates specifically. A lot of CRUD devs do not have formal comp sci backgrounds so it's somewhat understandable that they're not familiar with modulus. However, I can't think of a reason why a compsci grad wouldn't know it.

[1]http://www.codeproject.com/Tips/515367/Validate-credit-card-...

Even if you're unfamiliar with the modulus operator, it's not that hard to test divisibility.

C and sufficiently similar: x == k*(int)(x/k)

>My guess: it's the unfamiliarity of the mathematical modulus operator that trips most people up.

This is an interesting hypothesis, can anyone confirm that this is a particular sore spot? I wonder if that would show up as a generational gap? If the younger generations are working with web pages and never used much arithmetic, let alone remainders. But older generations grew up with low level graphics programming and arrays in languages like C and assembly where the modulus comes up all the time. So could we come up with the moral equivalent of FizzBuzz that a much larger percentage of the people who failed FizzBuzz could pass? And then I'd like to see how hard I'd think that test was.

I have done a fair share of interviewing and have asked people to do things similar to FizzBuzz in their own favourite language. When they fail, it's not about the details. (I don't mind mistakes, although I do ask and see if the candidate can spot them when given a hint.) It's amazing how many people completely and utterly fail at the task. They can't produce a loop, they can't come up with the necessary if statements, they can't even explain in pseudocode or verbally which steps need to be taken. They don't even know where to start. Sometimes it's because of anxiety or stress, but usually when it's an indication someone has no practical programming experience.

It means they can't succeed in writing the code. It's not a failure to understand how to use the IDE, or a failure to understand how to compile. It's that the applicant cannot actually write even the most basic code. The fact that this is so hard to believe and yet happens so often is what makes FizzBuzz so interesting.

I also wonder this same thing. I was asked to whiteboard fizzbuzz in pseudocode during an interview, and I actually made a slight mistake, I can't remember what it was now, but I think it would have duplicated the "FizzBuzz" lines. Overall, the accuracy of my 5 minute solution had little to no insight into how I would perform as a developer.

Now, if they were given time to actually compile code that ran a fizz buzz program and test it out before submitting it and STILL got it wrong...that might be questionable. But I think we need more information to really see if it was a bad assessment of their abilities or truly "bad" developers.

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