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 |
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| 28 | class Item |
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| 29 | { |
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| 30 | protected $identifier; |
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| 31 | protected $store; |
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| 32 | protected $tax; |
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| 33 | |||
| 34 | protected $data = []; |
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| 35 | |||
| 36 | /** |
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| 37 | * Construct the item. |
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| 38 | * |
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| 39 | * @param string $identifier |
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| 40 | * @param array $item |
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| 41 | * @param StorageInterface $store |
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| 42 | */ |
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| 43 | public function __construct($identifier, array $item, StorageInterface $store) |
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| 56 | |||
| 57 | /** |
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| 58 | * Return the value of protected methods. |
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| 59 | * |
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| 60 | * @param any $param |
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| 61 | * |
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| 62 | * @return mixed |
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| 63 | */ |
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| 64 | public function __get($param) |
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| 68 | |||
| 69 | /** |
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| 70 | * Update data array using set magic method. |
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| 71 | * |
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| 72 | * @param string $param The key to set |
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| 73 | * @param mixed $value The value to set $param to |
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| 74 | */ |
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| 75 | public function __set($param, $value) |
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| 82 | |||
| 83 | /** |
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| 84 | * Removes the current item from the cart. |
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| 85 | * |
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| 86 | * @return void |
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| 87 | */ |
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| 88 | public function remove() |
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| 92 | |||
| 93 | /** |
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| 94 | * Return the total tax for this item. |
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| 95 | * |
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| 96 | * @return float |
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| 97 | */ |
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| 98 | public function tax() |
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| 104 | |||
| 105 | /** |
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| 106 | * Return the total price for this item. |
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| 107 | * |
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| 108 | * @return float |
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| 109 | */ |
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| 110 | View Code Duplication | private function totalPrice() |
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| 124 | |||
| 125 | /** |
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| 126 | * Return the total of the item, with or without tax. |
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| 127 | * |
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| 128 | * @param bool $includeTax Whether or not to include tax |
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| 129 | * |
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| 130 | * @return float The total, as a float |
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| 131 | */ |
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| 132 | public function total($includeTax = true) |
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| 142 | |||
| 143 | /** |
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| 144 | * Return the total weight of the item. |
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| 145 | * |
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| 146 | * @return float The weight, as a float |
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| 147 | */ |
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| 148 | View Code Duplication | public function weight() |
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| 162 | |||
| 163 | /** |
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| 164 | * Return the total of the item, with or without tax. |
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| 165 | * |
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| 166 | * @param bool $includeTax Whether or not to include tax |
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| 167 | * |
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| 168 | * @return float The total, as a float |
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| 169 | */ |
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| 170 | public function single($includeTax = true) |
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| 188 | |||
| 189 | /** |
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| 190 | * Update a single key for this item, or multiple. |
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| 191 | * |
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| 192 | * @param array|string $key The array key to update, or an array of key-value pairs to update |
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| 193 | * @param null $value |
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| 194 | * |
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| 195 | * @return void |
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| 196 | */ |
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| 197 | public function update($key, $value = null) |
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| 211 | |||
| 212 | /** |
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| 213 | * Check if this item has options. |
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| 214 | * |
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| 215 | * @return bool Yes or no? |
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| 216 | */ |
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| 217 | public function hasOptions() |
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| 221 | |||
| 222 | /** |
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| 223 | * Convert the item into an array. |
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| 224 | * |
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| 225 | * @return array The item data |
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| 226 | */ |
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| 227 | public function toArray() |
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| 231 | } |
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| 232 |
Let’s take a look at an example: