3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $buffer = -1; function callback($output) { return 'R'; } ob_start('callback'); echo 'hello'; //$a = ob_get_contents(); echo $b = ob_get_clean(); var_dump($buffer);
Output for 4.3.0 - 5.6.21, hhvm-3.12.0, 7.0.0 - 7.1.0
helloint(-1)
Output for hhvm-3.10.0

Process exited with code 153.