3v4l.org

run code in 300+ PHP versions simultaneously
<?php<?php function on($method = "GET", $url, $callback) {} function on($method = "GET", $url, $callback) {} on();
Output for 5.3.0 - 5.3.28, 5.4.0 - 5.4.23
Fatal error: Cannot redeclare on() (previously declared in /in/H5oE3:2) in /in/H5oE3 on line 6
Process exited with code 255.
preferences:
178.66 ms | 1395 KiB | 60 Q