3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php var_dump(is_callable('f')); $a = null; $a(); f();
Output for 7.0.0 - 7.1.0
bool(false) Fatal error: Uncaught Error: Function name must be a string in /in/mTcBp:4 Stack trace: #0 {main} thrown in /in/mTcBp on line 4
Process exited with code 255.
Output for 5.0.0 - 5.6.28, hhvm-3.10.0 - 3.12.0
bool(false) Fatal error: Function name must be a string in /in/mTcBp on line 4
Process exited with code 255.
Output for 4.4.5 - 4.4.9
bool(false) Fatal error: Call to undefined function: () in /in/mTcBp on line 4
Process exited with code 255.
Output for 4.3.2 - 4.4.4
bool(false) Fatal error: Call to undefined function: () in /in/mTcBp on line 4
Process exited with code 255.
Output for 4.3.0 - 4.3.1
bool(false) Fatal error: Call to undefined function: () in /in/mTcBp on line 4