3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $n = 0 - 0.000000000000000000000000000000001; echo '$n: '; var_dump($n); echo 'round($n): '; var_dump(round($n));
Output for 5.2.1 - 5.3.3, 5.3.7 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
$n: float(-1.0E-33) round($n): float(-0)
Output for 4.3.3 - 5.2.0, 5.3.4 - 5.3.6
$n: float(-1.0E-33) round($n): float(0)
Output for 4.3.0 - 4.3.2
$n: float(-1.E-33) round($n): float(0)