3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = array("one" => 1, "two" => 2, "three" => 3, "four" => 4, "five" => 5); foreach($array as $key => &$val) { $val += 1; } var_dump($array);
Output for 5.2.1 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.8 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 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(5) { ["one"]=> int(2) ["two"]=> int(3) ["three"]=> int(4) ["four"]=> int(5) ["five"]=> &int(6) }
Output for 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0
array(5) { ["one"]=> &int(2) ["two"]=> &int(3) ["three"]=> &int(4) ["four"]=> &int(5) ["five"]=> &int(6) }
Output for 4.4.2 - 4.4.9
Parse error: syntax error, unexpected '&', expecting T_VARIABLE or '$' in /in/7hePH on line 4
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.3.11, 4.4.0 - 4.4.1
Parse error: parse error, unexpected '&', expecting T_VARIABLE or '$' in /in/7hePH 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/7hePH on line 4
Process exited with code 255.

preferences:
217.08 ms | 401 KiB | 330 Q