3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a1 = array(1, 2, 3); $a2 = $a1; $a2[0] = 5; print_r($a1); $a3 = &$a1; $a3[0] = 5; print_r($a1);

preferences:
79.75 ms | 402 KiB | 5 Q