3v4l.org

run code in 300+ PHP versions simultaneously
<?php usort(array('a', 'b', 'c', 'd'), 'some_sort_function'); function some_sort_function($a, $b) { static $foo = NULL; if ($foo === NULL) { $foo = 'bar'; echo "just once?\n"; } return 0; }
Output for 8.3.0 - 8.3.6
Fatal error: Uncaught Error: usort(): Argument #1 ($array) could not be passed by reference in /in/Ng8JL:3 Stack trace: #0 {main} thrown in /in/Ng8JL on line 3
Process exited with code 255.
Output for 8.1.23 - 8.1.28, 8.2.10 - 8.2.18
Fatal error: Uncaught Error: usort(): Argument #1 ($array) cannot be passed by reference in /in/Ng8JL:3 Stack trace: #0 {main} thrown in /in/Ng8JL on line 3
Process exited with code 255.
Output for 4.3.2 - 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 - 5.4.32
Fatal error: Only variables can be passed by reference in /in/Ng8JL on line 3
Process exited with code 255.
Output for 4.3.0 - 4.3.1
Fatal error: Only variables can be passed by reference in /in/Ng8JL on line 3
preferences:
107.47 ms | 401 KiB | 143 Q