3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = ['a', 'b']; usort($array, function ($firstValue, $secondValue) { echo "COMPARING: {$firstValue} with {$secondValue}\n"; return -1;});
Output for 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.30, 8.2.0 - 8.2.25, 8.3.0 - 8.3.14
COMPARING: a with b
Output for 5.6.0 - 5.6.40
COMPARING: b with a
preferences:
83.08 ms | 407 KiB | 5 Q