3v4l.org

run code in 300+ PHP versions simultaneously
<?php function foo(&$a) { $a = 10; var_dump(debug_backtrace()); } $x = 5; foo($x);
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
array(1) { [0]=> array(4) { ["file"]=> string(9) "/in/fOrXL" ["line"]=> int(9) ["function"]=> string(3) "foo" ["args"]=> array(1) { [0]=> int(10) } } }
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 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.10, 7.2.29 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33
array(1) { [0]=> array(4) { ["file"]=> string(9) "/in/fOrXL" ["line"]=> int(9) ["function"]=> string(3) "foo" ["args"]=> array(1) { [0]=> &int(10) } } }

preferences:
191.17 ms | 405 KiB | 351 Q