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:
Complex classes like WC_Order_Item often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use WC_Order_Item, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 17 | class WC_Order_Item extends WC_Data implements ArrayAccess { |
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| 18 | |||
| 19 | /** |
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| 20 | * Data array, with defaults. |
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| 21 | * @since 2.7.0 |
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| 22 | * @var array |
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| 23 | */ |
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| 24 | protected $_data = array( |
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| 25 | 'order_id' => 0, |
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| 26 | 'order_item_id' => 0, |
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| 27 | 'name' => '', |
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| 28 | 'type' => '', |
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| 29 | ); |
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| 30 | |||
| 31 | /** |
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| 32 | * May store an order to prevent retriving it multiple times. |
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| 33 | * @var object |
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| 34 | */ |
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| 35 | protected $_order; |
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| 36 | |||
| 37 | /** |
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| 38 | * Stores meta in cache for future reads. |
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| 39 | * A group must be set to to enable caching. |
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| 40 | * @var string |
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| 41 | */ |
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| 42 | protected $_cache_group = 'order_itemmeta'; |
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| 43 | |||
| 44 | /** |
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| 45 | * Meta type. This should match up with |
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| 46 | * the types avaiable at https://codex.wordpress.org/Function_Reference/add_metadata. |
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| 47 | * WP defines 'post', 'user', 'comment', and 'term'. |
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| 48 | */ |
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| 49 | protected $_meta_type = 'order_item'; |
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| 50 | |||
| 51 | /** |
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| 52 | * Constructor. |
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| 53 | * @param int|object|array $order_item ID to load from the DB (optional) or already queried data. |
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| 54 | */ |
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| 55 | public function __construct( $item = 0 ) { |
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| 66 | |||
| 67 | /** |
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| 68 | * Set all data based on input array. |
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| 69 | * @param array $data |
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| 70 | * @access private |
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| 71 | */ |
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| 72 | public function set_all( $data ) { |
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| 81 | |||
| 82 | /** |
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| 83 | * Type checking |
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| 84 | * @param string|array $Type |
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| 85 | * @return boolean |
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| 86 | */ |
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| 87 | public function is_type( $type ) { |
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| 90 | |||
| 91 | /** |
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| 92 | * Get qty. |
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| 93 | * @return int |
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| 94 | */ |
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| 95 | public function get_qty() { |
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| 98 | |||
| 99 | /** |
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| 100 | * Get parent order object. |
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| 101 | * @return int |
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| 102 | */ |
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| 103 | public function get_order() { |
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| 109 | |||
| 110 | /* |
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| 111 | |-------------------------------------------------------------------------- |
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| 112 | | Getters |
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| 113 | |-------------------------------------------------------------------------- |
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| 114 | */ |
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| 115 | |||
| 116 | /** |
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| 117 | * Get order item ID. |
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| 118 | * @return int |
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| 119 | */ |
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| 120 | public function get_id() { |
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| 123 | |||
| 124 | /** |
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| 125 | * Get order ID this meta belongs to. |
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| 126 | * @return int |
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| 127 | */ |
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| 128 | public function get_order_id() { |
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| 131 | |||
| 132 | /** |
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| 133 | * Get order item ID this meta belongs to. |
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| 134 | * @return int |
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| 135 | */ |
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| 136 | protected function get_order_item_id() { |
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| 139 | |||
| 140 | /** |
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| 141 | * Get order item name. |
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| 142 | * @return string |
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| 143 | */ |
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| 144 | public function get_name() { |
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| 147 | |||
| 148 | /** |
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| 149 | * Get order item type. |
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| 150 | * @return string |
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| 151 | */ |
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| 152 | public function get_type() { |
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| 155 | |||
| 156 | /* |
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| 157 | |-------------------------------------------------------------------------- |
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| 158 | | Setters |
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| 159 | |-------------------------------------------------------------------------- |
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| 160 | */ |
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| 161 | |||
| 162 | /** |
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| 163 | * Set ID |
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| 164 | * @param int $value |
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| 165 | */ |
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| 166 | public function set_id( $value ) { |
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| 169 | |||
| 170 | /** |
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| 171 | * Set order ID. |
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| 172 | * @param int $value |
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| 173 | */ |
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| 174 | public function set_order_id( $value ) { |
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| 177 | |||
| 178 | /** |
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| 179 | * Set order item ID. |
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| 180 | * @param int $value |
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| 181 | */ |
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| 182 | protected function set_order_item_id( $value ) { |
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| 185 | |||
| 186 | /** |
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| 187 | * Set order item name. |
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| 188 | * @param string $value |
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| 189 | */ |
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| 190 | public function set_name( $value ) { |
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| 193 | |||
| 194 | /** |
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| 195 | * Set order item type. |
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| 196 | * @param string $value |
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| 197 | */ |
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| 198 | protected function set_type( $value ) { |
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| 201 | |||
| 202 | /* |
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| 203 | |-------------------------------------------------------------------------- |
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| 204 | | CRUD methods |
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| 205 | |-------------------------------------------------------------------------- |
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| 206 | | |
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| 207 | | Methods which create, read, update and delete data from the database. |
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| 208 | | |
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| 209 | */ |
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| 210 | |||
| 211 | /** |
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| 212 | * Insert data into the database. |
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| 213 | * @since 2.7.0 |
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| 214 | */ |
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| 215 | View Code Duplication | public function create() { |
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| 227 | |||
| 228 | /** |
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| 229 | * Update data in the database. |
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| 230 | * @since 2.7.0 |
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| 231 | */ |
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| 232 | View Code Duplication | public function update() { |
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| 243 | |||
| 244 | /** |
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| 245 | * Read from the database. |
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| 246 | * @since 2.7.0 |
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| 247 | * @param int|object $item ID of object to read, or already queried object. |
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| 248 | */ |
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| 249 | public function read( $item ) { |
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| 268 | |||
| 269 | /** |
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| 270 | * Save data to the database. |
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| 271 | * @since 2.7.0 |
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| 272 | * @return int Item ID |
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| 273 | */ |
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| 274 | public function save() { |
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| 284 | |||
| 285 | /** |
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| 286 | * Delete data from the database. |
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| 287 | * @since 2.7.0 |
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| 288 | */ |
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| 289 | public function delete() { |
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| 298 | |||
| 299 | /* |
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| 300 | |-------------------------------------------------------------------------- |
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| 301 | | Meta Data Handling |
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| 302 | |-------------------------------------------------------------------------- |
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| 303 | */ |
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| 304 | |||
| 305 | /** |
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| 306 | * Expands things like term slugs before return. |
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| 307 | * @param string $hideprefix (default: _) |
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| 308 | * @return array |
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| 309 | */ |
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| 310 | public function get_formatted_meta_data( $hideprefix = '_' ) { |
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| 340 | |||
| 341 | /* |
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| 342 | |-------------------------------------------------------------------------- |
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| 343 | | Array Access Methods |
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| 344 | |-------------------------------------------------------------------------- |
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| 345 | | |
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| 346 | | For backwards compat with legacy arrays. |
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| 347 | | |
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| 348 | */ |
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| 349 | |||
| 350 | /** |
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| 351 | * offsetSet for ArrayAccess |
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| 352 | * @param string $offset |
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| 353 | * @param mixed $value |
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| 354 | */ |
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| 355 | public function offsetSet( $offset, $value ) { |
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| 369 | |||
| 370 | /** |
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| 371 | * offsetUnset for ArrayAccess |
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| 372 | * @param string $offset |
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| 373 | */ |
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| 374 | public function offsetUnset( $offset ) { |
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| 386 | |||
| 387 | /** |
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| 388 | * offsetExists for ArrayAccess |
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| 389 | * @param string $offset |
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| 390 | * @return bool |
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| 391 | */ |
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| 392 | public function offsetExists( $offset ) { |
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| 398 | |||
| 399 | /** |
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| 400 | * offsetGet for ArrayAccess |
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| 401 | * @param string $offset |
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| 402 | * @return mixed |
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| 403 | */ |
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| 404 | public function offsetGet( $offset ) { |
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| 428 | } |
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| 429 |
This check looks for PHPDoc comments describing methods or function parameters that do not exist on the corresponding method or function.
Consider the following example. The parameter
$italyis not defined by the methodfinale(...).The most likely cause is that the parameter was removed, but the annotation was not.