3v4l.org

run code in 300+ PHP versions simultaneously
<?php $foo = "hello"; function modify($a) { global $foo; var_dump($a === $foo); $a = "world"; var_dump($a === $foo); } modify($foo); var_dump($foo);
Output for 7.1.25 - 7.1.28, 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
bool(true) bool(false) string(5) "hello"

preferences:
156.75 ms | 407 KiB | 5 Q