3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = 3; $b = 4; list($b, $a) = [ $a, $b]; echo "a=$a b=$b\n";
Output for 7.1.25 - 7.1.32, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
a=4 b=3

preferences:
102.62 ms | 1455 KiB | 4 Q