Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
| 1 | <?php | ||
| 20 | class ClosingDate | ||
| 21 | { | ||
| 22 | protected $timezone; | ||
| 23 | |||
| 24 | public function __construct(DateTimeZone $timezone) | ||
| 28 | |||
| 29 | View Code Duplication | public function parse(DOMDocument $dom, DOMXPath $xpath) : DateTimeImmutable | |
| 44 | |||
| 45 | private function clearClosingHour(string $closingHour) : string | ||
| 49 | } | ||
| 50 | 
This check looks from parameters that have been defined for a function or method, but which are not used in the method body.