3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $f = function($x) use($f){ if($x==0 || $x==1) return 1; return $f($x-1) + $f($x-2); }; print $f(10);
Output for 7.0.0 - 7.1.0
Notice: Undefined variable: f in /in/cO2ER on line 3 Fatal error: Uncaught Error: Function name must be a string in /in/cO2ER:6 Stack trace: #0 /in/cO2ER(9): {closure}(10) #1 {main} thrown in /in/cO2ER on line 6
Process exited with code 255.
Output for hhvm-3.12.0
Notice: Undefined variable: f in /in/cO2ER on line 7 Fatal error: Function name must be a string in /in/cO2ER on line 6
Process exited with code 255.
Output for hhvm-3.10.0

Process exited with code 153.
Output for 5.3.0 - 5.6.28
Notice: Undefined variable: f in /in/cO2ER on line 3 Fatal error: Function name must be a string in /in/cO2ER on line 6
Process exited with code 255.
Output for 4.4.2 - 4.4.9, 5.1.0 - 5.2.17
Parse error: syntax error, unexpected T_FUNCTION in /in/cO2ER on line 3
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.4.1, 5.0.0 - 5.0.5
Parse error: parse error, unexpected T_FUNCTION in /in/cO2ER on line 3
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error in /in/cO2ER on line 3
Process exited with code 255.