<?php
function getWaterState($degrees, $scale = 'celsius')
{
  $celsiusDegrees = $scale == 'fahrenheit'
    ? $degrees * 1.8 + 32
    : $degrees;

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

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

  return 'This is liquid water';
}