3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php var_dump(json_decode(json_encode("\u2028\u2029", JSON_UNESCAPED_UNICODE )));
based on r2kJM
Output for 5.6.0 - 7.3.0beta1
string(12) "\u2028\u2029"