3v4l.org

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<?php error_reporting(-1); function myCheckA($in) { return isset($in); } function myCheck($in) { global $$in; return isset($$in); } $var1='Something'; $var2='var1'; echo 'Set: ' . isset($$var2), "\n"; $var2='nope'; echo 'Set: ' . isset($$var2), "\n"; $var2='var1'; echo 'Set: ' . myCheck($var2), "\n"; $var2='nope'; echo 'Set: ' . myCheck($var2), "\n"; ?>

preferences:
35.55 ms | 402 KiB | 5 Q