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run code in 200+ php & hhvm versions
Bugs & Features
<?php $x = ''; $$x = 'empty'; var_dump( ${''} ); $x = 'red'; $$x = 'empty'; var_dump( ${'red'} );
based on Wdrs6
Output for 4.3.0 - 7.2.0
string(5) "empty" string(5) "empty"