3v4l.org

run code in 300+ PHP versions simultaneously
<?php $b = "hello"; $x = array(); $x[0] =& $b; $x[1] =& $b; $y = unserialize(serialize($x)); $y[0] = 'world'; $x[0] = 'world'; var_dump($x); var_dump($y);
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, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 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 - 8.3.7
array(2) { [0]=> &string(5) "world" [1]=> &string(5) "world" } array(2) { [0]=> &string(5) "world" [1]=> &string(5) "world" }
preferences:
277.69 ms | 406 KiB | 461 Q