3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = 0; $b = 1; echo "foo ", $a^$b, "\n"; echo "a | b\n"; for($i = 0; $i < 4; $i++){ list($a, $b) = str_split(str_pad(decbin($i), 2, 0, STR_PAD_LEFT)); echo "$a | $b | ", $a^$b, "\n"; }
Output for 5.4.2 - 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, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
foo 1 a | b 0 | 0 | 0 | 1 |  1 | 0 |  1 | 1 |
preferences:
185.61 ms | 404 KiB | 257 Q