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<?php error_reporting(E_ALL); ini_set('display_errors', true); function by_ref(&$value) { echo "Call by ref value:\n"; var_dump($value); } function by_value($value) { echo "Call by value value:\n"; var_dump($value); } $thing = array(1,2); echo "Before call by ref:\n"; var_dump($thing); by_ref($thing[5][6]); echo "After call by ref:\n"; var_dump($thing); echo "Before call by value\n"; by_value($thing[7][8]); echo "After call by value:\n"; var_dump($thing); echo "Before call by ref again:\n"; by_ref($thing[7][8]); echo "After call by ref again:\n"; var_dump($thing); echo "isset:\n"; var_dump(isset($thing[9][10]));

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