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run code in 150+ php & hhvm versions
Bugs & Features
<?php var_dump(mb_convert_case('asdf', MB_CASE_UPPER, null));
based on dktGi
Output for 5.2.6 - 5.6.28, 7.0.0 - 7.1.0
Warning: mb_convert_case(): Unknown encoding "(null)" in /in/NBmli on line 3 bool(false)
Output for 4.3.0 - 5.2.5, hhvm-3.10.0 - 3.12.0
string(4) "ASDF"