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run code in 150+ php & hhvm versions
Bugs & Features
<?php var_dump(strtoupper(null));
Output for 4.3.0 - 5.6.28, hhvm-3.10.0, 7.0.0 - 7.1.0
string(0) ""
Output for hhvm-3.12.0
Warning: strtoupper() expects parameter 1 to be string, null given in /in/ONLBM on line 3 NULL