3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = array('abe','ben','cam'); foreach ($a as $k=>&$n) $n = strtoupper($n); foreach ($a as $k=>$n) // notice NO reference here! echo "$n\n"; print_r($a); ?>
Output for 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 - 8.3.6
ABE BEN BEN Array ( [0] => ABE [1] => BEN [2] => BEN )
Output for 4.4.2 - 4.4.9
Parse error: syntax error, unexpected '&', expecting T_VARIABLE or '$' in /in/MjbGm on line 4
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.3.11, 4.4.0 - 4.4.1
Parse error: parse error, unexpected '&', expecting T_VARIABLE or '$' in /in/MjbGm on line 4
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error, expecting `T_VARIABLE' or `'$'' in /in/MjbGm on line 4
Process exited with code 255.
preferences:
310.8 ms | 401 KiB | 459 Q