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run code in 200+ php & hhvm versions
Bugs & Features
<?php $php = ""; $i = 0; function f() { global $php; global $i; $i++; if($i > 5) { return $php; } return "\${" . f() . "}"; } var_dump(f());
based on 0qQkj
Output for 4.3.0 - 7.2.0
string(15) "${${${${${}}}}}"