FizzBuzz

<?php

function fizzbuzz($n) {
  if ($n) {
    if (!($n % 3)) {
      $fizzbuzz .= 'Fizz';
    }

    if (!($n % 5)) {
      $fizzbuzz .= 'Buzz';
    }

    return $fizzbuzz;
  }

  return '';
}

for ($n = 0; $n <= 100; $n++) {
  echo $n . ': ';
  echo fizzbuzz($n);
  echo "\n";
}

function fizzbuzzTest() {
  echo (fizzbuzz(0) == '' ? 'passed' : 'failed') . "\n";
  echo (fizzbuzz(3) == 'Fizz' ? 'passed' : 'failed') . "\n";
  echo (fizzbuzz(6) == 'Fizz' ? 'passed' : 'failed') . "\n";
  echo (fizzbuzz(5) == 'Buzz' ? 'passed' : 'failed') . "\n";
  echo (fizzbuzz(10) == 'Buzz' ? 'passed' : 'failed') . "\n";
  echo (fizzbuzz(15) == 'FizzBuzz' ? 'passed' : 'failed') . "\n";
  echo (fizzbuzz(30) == 'FizzBuzz' ? 'passed' : 'failed') . "\n";
  echo (fizzbuzz(31) == '' ? 'passed' : 'failed') . "\n";
}

fizzbuzzTest();