3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php var_dump(mb_substr('$𝄞𝄞', 0, 7));
based on FX3lZ
Output for 5.6.7 - 5.6.28, hhvm-3.12.0, 7.0.0 - 7.1.0
string(9) "$𝄞𝄞"
Output for hhvm-3.10.0

Process exited with code 153.
Output for 4.3.0 - 5.5.35
string(7) "$𝄞�"