3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = 1; $x = 2; function test() { global $a; global $x; $GLOBALS['a'] = &$x; $x = 5; echo $a . PHP_EOL; echo $x . PHP_EOL; } test(); echo PHP_EOL; echo $a . PHP_EOL; // $a is 1 here instead of 5 echo $x . PHP_EOL; $a = &$x; echo PHP_EOL; echo $a . PHP_EOL; echo $x . PHP_EOL;
Output for 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 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.26, 8.4.1 - 8.4.13
1 5 5 5 5 5

preferences:
170.73 ms | 407 KiB | 5 Q