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 | ||
| 15 | class UserController extends Controller | ||
| 16 | { | ||
| 17 | /** | ||
| 18 | * Constructor | ||
| 19 | */ | ||
| 20 | public function __construct() | ||
| 21 |     { | ||
| 22 | parent::__construct(); | ||
| 23 | |||
| 24 | $action = Route::getFacadeRoot()->current()->getActionMethod(); | ||
| 25 | |||
| 26 |         if (in_array($action, ['index', 'show'])) { | ||
| 27 |             $this->breadcrumbs->addCrumb('Users', route('users.user.index')); | ||
|  | |||
| 28 | } | ||
| 29 | } | ||
| 30 | |||
| 31 | /** | ||
| 32 | * Show all the users. | ||
| 33 | * | ||
| 34 | * @return \Illuminate\View\View | ||
| 35 | */ | ||
| 36 | public function index(): View | ||
| 40 | |||
| 41 | /** | ||
| 42 | * Show the user profile page. | ||
| 43 | * | ||
| 44 | * @param string $slug The slug of the user. | ||
| 45 | * | ||
| 46 | * @return \Illuminate\Http\RedirectResponse|\Illuminate\View\View | ||
| 47 | */ | ||
| 48 | public function show(Request $request, string $slug) | ||
| 77 | |||
| 78 | /** | ||
| 79 | * Show the settings form. | ||
| 80 | * | ||
| 81 | * @return \Illuminate\View\View | ||
| 82 | */ | ||
| 83 | public function showSettingsForm(): View | ||
| 91 | |||
| 92 | /** | ||
| 93 | * Handle an update request for the user. | ||
| 94 | * | ||
| 95 | * @param \Illuminate\Http\Request $request | ||
| 96 | * | ||
| 97 | * @return \Illuminate\Http\RedirectResponse | ||
| 98 | */ | ||
| 99 | public function update(Request $request): RedirectResponse | ||
| 116 | |||
| 117 | /** | ||
| 118 | * Handle the delete request for the user. | ||
| 119 | * | ||
| 120 | * @param \Illuminate\Http\Request $request | ||
| 121 | * | ||
| 122 | * @return \Illuminate\Http\RedirectResponse | ||
| 123 | */ | ||
| 124 | View Code Duplication | public function delete(Request $request): RedirectResponse | |
| 145 | |||
| 146 | /** | ||
| 147 | * Handle a E-mail update request for the user. | ||
| 148 | * | ||
| 149 | * @param \Illuminate\Http\Request $request | ||
| 150 | * | ||
| 151 | * @return \Illuminate\Http\RedirectResponse | ||
| 152 | */ | ||
| 153 | protected function updateEmail(Request $request): RedirectResponse | ||
| 162 | |||
| 163 | /** | ||
| 164 | * Handle a Password update request for the user. | ||
| 165 | * | ||
| 166 | * @param \Illuminate\Http\Request $request | ||
| 167 | * | ||
| 168 | * @return \Illuminate\Http\RedirectResponse | ||
| 169 | */ | ||
| 170 | protected function updatePassword(Request $request): RedirectResponse | ||
| 187 | } | ||
| 188 | 
In PHP it is possible to write to properties without declaring them. For example, the following is perfectly valid PHP code:
Generally, it is a good practice to explictly declare properties to avoid accidental typos and provide IDE auto-completion: