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<?php $data[] = null; $data[] = 0; $data[] = 1; $data[] = true; $data[] = false; foreach($data as $value) { $result = is_null($value); echo "is_null ( ", var_export($value, true), " ) = ", var_export(is_null($value), true), " \n";}

preferences:
38.88 ms | 402 KiB | 5 Q