Fizz-Buzz Test

The "Fizz-Buzz test" is an interview question designed to help filter out the 99.5% of programming job candidates who can't seem to program their way out of a wet paper bag. The text of the programming assignment is as follows:

Write a program that prints the numbers from 1 to 100. But for multiples of three print "Fizz" instead of the number and for the multiples of five print "Buzz". For numbers which are multiples of both three and five print "FizzBuzz"?.

Why Fizz-Buzz is "hard:"

We can't understand why so many people "fail" the Fizz-Buzz test unless we understand why it is "hard" (for them). Understanding that, we may be able to evaluate the usefulness of this tool, and others, as filtering tools for candidates. Fizz-Buzz is "hard" for some programmers because:

  1. it doesn't fit into any of the patterns that were given to them in school assignments,
  2. it isn't possible to directly and simply represent the necessary tests, without duplication, in just about any commonly-used modern programming language.

To further illuminate both point 1 and 2:

  1. that it doesn't match the patterns they memorized from lectures and class assignments: I think this makes it a good discriminator, because I wish to hire candidates who can think for themselves -- not those who are limited to copying solutions from others.
  2. that it's hard to directly code it.

Fizz-Buzz does not fall into the common pattern of:


  if 1 then A
  else if 2 then B
  else if 3 then C
  else/otherwise D

(Well-- it could, but not when you consider "1,2 & 3" to be atomic tests, like "is divisible by 3.")

So I'm going to try to do this first in PHP,
I will print a table out of the resultant code below the code blocks.

//quick server-side php code...
$fizz = "fizz";
$buzz = "buzz";
for ( $x=1; $x<=100; $x++){
	switch($x){
        case ($x % 3 == 0 && $x % 5 == 0): 
            echo $fizz.$buzz;
            break;
        case ($x % 3 == 0): 
            echo $fizz;
            break;
        case ($x % 5 == 0): 
            echo $buzz;
            break;
        default:
            echo $x;
            break;
    }
}

FizzBuzz in Javascript

So, here is another example of some quick code client-side in javascript.

//I mimic'd the PHP code closely here, of course, you can do more with this...
var fizz = "fizz";
var buzz = "buzz";

for (i=1;i<=100;i++){
    switch (i){
        case (i % 3 == 0 && i % 5 == 0): 
            document. write( fizz + buzz );
            break;
        case (i % 3 == 0): 
            document. write( fizz );
            break;
        case (i % 5 == 0): 
            document. write( buzz );
            break;
        default : 
            document. write( i );
    }
}

Code output Results:


Write a program that prints the numbers from 1 to 100. 
But for multiples of three print "Fizz" instead of the number 
and for the multiples of five print "Buzz". 
For numbers which are multiples of both three and five print "FizzBuzz"?




 1  2  fizz  4  buzz  fizz  7  8  fizz  buzz  11  fizz  13  14  fizzbuzz 
 16  17  fizz  19  buzz  fizz  22  23  fizz  buzz  26  fizz  28  29  fizzbuzz 
 31  32  fizz  34  buzz  fizz  37  38  fizz  buzz  41  fizz  43  44  fizzbuzz 
 46  47  fizz  49  buzz  fizz  52  53  fizz  buzz  56  fizz  58  59  fizzbuzz 
 61  62  fizz  64  buzz  fizz  67  68  fizz  buzz  71  fizz  73  74  fizzbuzz 
 76  77  fizz  79  buzz  fizz  82  83  fizz  buzz  86  fizz  88  89  fizzbuzz 
 91  92  fizz  94  buzz  fizz  97  98  fizz  buzz

Final Thoughts

Well, that is it. I really enjoyed going through this with you. Please drop me a line if you benefitted from the information given. Stay curious!