3v4l.org

run code in 300+ PHP versions simultaneously
<?php var_dump(pow(2, 1/2), pow(2, 2/2), pow(2, 3/2), pow(2, 4/2), pow(2, 5/2), pow(2, 6/2), pow(2, 7/2), pow(2, 8/2), pow(2, 9/2));
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
float(1.4142135623730951) int(2) float(2.8284271247461903) int(4) float(5.656854249492381) int(8) float(11.313708498984761) int(16) float(22.627416997969522)
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33
float(1.4142135623731) int(2) float(2.8284271247462) int(4) float(5.6568542494924) int(8) float(11.313708498985) int(16) float(22.62741699797)

preferences:
195.52 ms | 404 KiB | 339 Q