split-function.php

<?php
function convertToCelsiusDegrees($degrees, $scale = 'celsius')
{
  if ($scale == 'fahrenheit') {
    return $degrees * 1.8 + 32;
  }

  return $degrees;
}

function getWaterState($degrees, $scale = 'celsius')
{
  $celsiusDegrees = convertToCelsiusDegrees($degrees, $scale);

  if ($celsiusDegrees < 0) {
    return 'This is solid ice';
  }

  if ($celsiusDegrees > 100) {
    return 'This is gaz water';
  }

  return 'This is liquid water';
}