3v4l.org

run code in 300+ PHP versions simultaneously
<?php putenv('FOO=BAR'); echo getenv('FOO') . PHP_EOL; putenv('FOO=BAZ'); echo getenv('FOO') . PHP_EOL;
Output for 7.0.0 - 7.0.25, 7.1.0 - 7.1.33, 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 - 8.1.27, 8.2.0 - 8.2.16, 8.3.0 - 8.3.3
BAR BAZ

preferences:
144.07 ms | 404 KiB | 219 Q