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<?php function modify(&$x) { $x = 50; } function &get_reference() { global $x; return $x; } $x = 42; var_dump($x); modify(get_reference()); var_dump($x); print "======"; $x = 42; var_dump($x); modify((get_reference())); // brackets var_dump($x); ?>

preferences:
38.85 ms | 402 KiB | 5 Q