3v4l.org

run code in 300+ PHP versions simultaneously
<?php function foo() { var_dump(debug_backtrace()); } call_user_func('foo');
Output for 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 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
array(1) { [0]=> array(4) { ["file"]=> string(9) "/in/4fp6e" ["line"]=> int(8) ["function"]=> string(3) "foo" ["args"]=> array(0) { } } }
Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40
array(2) { [0]=> array(2) { ["function"]=> string(3) "foo" ["args"]=> array(0) { } } [1]=> array(4) { ["file"]=> string(9) "/in/4fp6e" ["line"]=> int(8) ["function"]=> string(14) "call_user_func" ["args"]=> array(1) { [0]=> &string(3) "foo" } } }

preferences:
313.37 ms | 403 KiB | 385 Q