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 ArrayHelper 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 ArrayHelper, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 14 | class ArrayHelper |
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| 15 | { |
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| 16 | /** |
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| 17 | * Recursive safe merge. |
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| 18 | * Based on Yii2 yii\helpers\BaseArrayHelper::merge. |
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| 19 | * |
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| 20 | * Merges two or more arrays into one recursively. |
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| 21 | * If each array has an element with the same string key value, the latter |
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| 22 | * will overwrite the former (different from array_merge_recursive). |
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| 23 | * Recursive merging will be conducted if both arrays have an element of array |
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| 24 | * type and are having the same key. |
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| 25 | * For integer-keyed elements, the elements from the latter array will |
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| 26 | * be appended to the former array. |
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| 27 | * |
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| 28 | * @param array $a array to be merged to |
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| 29 | * @param array $b array to be merged from |
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| 30 | * |
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| 31 | * @return array the merged array |
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| 32 | */ |
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| 33 | public static function merge($a, $b) |
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| 58 | |||
| 59 | /** |
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| 60 | * Get specified items as array. |
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| 61 | * |
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| 62 | * @param mixed $keys specification |
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| 63 | * |
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| 64 | * @return array |
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| 65 | */ |
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| 66 | public static function getItems($array, $keys = null) |
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| 81 | /** |
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| 82 | * Inserts items in front of array. |
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| 83 | * rough method: unset and then set, think of better. |
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| 84 | */ |
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| 85 | public static function insertLast(array $array, array $items) |
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| 96 | |||
| 97 | /** |
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| 98 | * Inserts items in front of array. |
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| 99 | * rough method: unset and then set, think of better. |
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| 100 | */ |
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| 101 | public static function insertFirst(array $array, array $items) |
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| 110 | |||
| 111 | /** |
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| 112 | * Inserts items inside of array. |
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| 113 | * rough method: unset and then set, think of better. |
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| 114 | * |
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| 115 | * @param array $array source array |
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| 116 | * @param array $items array of items. |
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| 117 | * @param string|array $where where to insert |
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| 118 | * |
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| 119 | * @return array new items list |
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| 120 | * |
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| 121 | * @see add() |
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| 122 | */ |
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| 123 | public static function insertInside(array $array, $items, $where) |
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| 156 | |||
| 157 | /** |
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| 158 | * Internal function to prepare where list for insertInside. |
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| 159 | * |
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| 160 | * @param array $array source array |
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| 161 | * @param array|string $list array to convert |
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| 162 | * |
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| 163 | * @return array |
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| 164 | */ |
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| 165 | protected static function prepareWhere(array $array, $list) |
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| 178 | |||
| 179 | /** |
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| 180 | * Recursively removes duplicate values from non-associative arrays. |
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| 181 | */ |
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| 182 | public static function unique($array) |
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| 195 | |||
| 196 | /** |
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| 197 | * Non-recursively removes duplicate values from non-associative arrays. |
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| 198 | */ |
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| 199 | public static function uniqueFlat($array) |
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| 214 | |||
| 215 | public static function toArray($object) |
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| 226 | } |
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| 227 |
This check looks from parameters that have been defined for a function or method, but which are not used in the method body.