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 Transform 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 Transform, and based on these observations, apply Extract Interface, too.
1 | <?php |
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8 | class Transform |
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9 | { |
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10 | /** |
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11 | * Dotted array cache. |
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12 | * |
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13 | * @var array |
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14 | */ |
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15 | protected $dotted = []; |
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16 | |||
17 | /** |
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18 | * A instance of Access |
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19 | * |
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20 | * @var \Narrowspark\Arr\Access |
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21 | */ |
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22 | protected $access; |
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23 | |||
24 | /** |
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25 | * A instance of Access |
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26 | * |
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27 | * @var \Narrowspark\Arr\Enumerator |
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28 | */ |
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29 | protected $enumerator; |
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30 | |||
31 | public function __construct() |
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36 | |||
37 | /** |
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38 | * Pop value from sub array. |
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39 | * |
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40 | * @param array $array |
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41 | * @param string $key |
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42 | * |
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43 | * @return mixed |
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44 | */ |
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45 | public static function pop(array $array, $key) |
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63 | |||
64 | /** |
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65 | * Swap two elements between positions. |
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66 | * |
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67 | * @param array $array array to swap |
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68 | * @param string $swapA |
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69 | * @param string $swapB |
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70 | * |
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71 | * @return array|null |
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72 | */ |
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73 | public function swap(array $array, $swapA, $swapB) |
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79 | |||
80 | /** |
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81 | * Create a new array consisting of every n-th element. |
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82 | * |
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83 | * @param array $array |
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84 | * @param int $step |
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85 | * @param int $offset |
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86 | * |
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87 | * @return array |
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88 | */ |
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89 | public static function every($array, $step, $offset = 0) |
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105 | |||
106 | /** |
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107 | * Indexes an array depending on the values it contains. |
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108 | * |
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109 | * @param array $array |
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110 | * @param callable $callback Function to combine values. |
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111 | * @param bool $overwrite Should duplicate keys be overwritten? |
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112 | * |
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113 | * @return array Indexed values. |
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114 | */ |
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115 | public function combine(array $array, callable $callback, $overwrite = true) |
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134 | |||
135 | /** |
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136 | * Collapse a nested array down to an array of flat key=>value pairs |
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137 | */ |
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138 | public function collapse(array $array) |
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157 | |||
158 | /** |
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159 | * Divide an array into two arrays. One with keys and the other with values. |
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160 | * |
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161 | * @param array $array |
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162 | * |
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163 | * @return array[] |
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164 | */ |
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165 | public function divide($array) |
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169 | |||
170 | /** |
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171 | * Stripe all empty items. |
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172 | * |
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173 | * @param array $array |
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174 | * |
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175 | * @return array |
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176 | */ |
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177 | public function stripEmpty(array $array) |
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191 | |||
192 | /** |
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193 | * Remove all instances of $ignore found in $elements (=== is used). |
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194 | * |
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195 | * @param array $array |
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196 | * @param array $ignore |
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197 | * |
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198 | * @return array |
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199 | */ |
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200 | public function without(array $array, array $ignore) |
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210 | |||
211 | /** |
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212 | * Reindexes a list of values. |
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213 | * |
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214 | * @param array $array |
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215 | * @param array $map An map of correspondances of the form |
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216 | * ['currentIndex' => 'newIndex']. |
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217 | * @param bool $unmapped Whether or not to keep keys that are not |
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218 | * remapped. |
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219 | * |
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220 | * @return array |
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221 | */ |
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222 | public function reindex(array $array, array $map, $unmapped = true) |
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236 | |||
237 | /** |
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238 | * Merges two or more arrays into one recursively. |
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239 | * |
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240 | * @param array $arrays. |
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241 | * |
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242 | * @return array |
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243 | */ |
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244 | public function merge(array $arrays) |
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265 | |||
266 | /** |
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267 | * Makes every value that is numerically indexed a key, given $default |
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268 | * as value. |
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269 | * |
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270 | * @param array $array |
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271 | * @param mixed $default |
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272 | * |
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273 | * @return array |
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274 | */ |
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275 | public function normalize(array $array, $default) |
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290 | |||
291 | /** |
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292 | * Extend one array with another. |
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293 | * |
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294 | * @param array $arrays |
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295 | * |
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296 | * @return array |
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297 | */ |
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298 | public function extend(array $arrays) |
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314 | |||
315 | /** |
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316 | * Transforms a 1-dimensional array into a multi-dimensional one, |
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317 | * exploding keys according to a separator. |
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318 | * |
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319 | * @param array $array |
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320 | * |
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321 | * @return array |
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322 | */ |
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323 | public function asHierarchy(array $array) |
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345 | |||
346 | /** |
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347 | * Separates elements from an array into groups. |
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348 | * The function maps an element to the key that will be used for grouping. |
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349 | * If no function is passed, the element itself will be used as key. |
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350 | * |
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351 | * @param array $array |
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352 | * @param callable|null $callback |
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353 | * |
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354 | * @return array |
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355 | */ |
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356 | public function groupBy(array $array, callable $callback = null) |
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378 | |||
379 | /** |
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380 | * Flatten a multi-dimensional associative array with dots. |
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381 | * |
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382 | * @param array $array |
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383 | * @param string $prepend |
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384 | * |
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385 | * @return array |
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386 | */ |
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387 | public function dot($array, $prepend = '') |
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407 | |||
408 | /** |
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409 | * Flatten a nested array to a separated key. |
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410 | * |
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411 | * @param array $array |
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412 | * @param string|null $separator |
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413 | * @param string $prepend |
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414 | * |
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415 | * @return array |
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416 | */ |
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417 | public function flatten(array $array, $separator = null, $prepend = '') |
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431 | |||
432 | /** |
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433 | * Expand a flattened array with dots to a multi-dimensional associative array. |
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434 | * |
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435 | * @param array $array |
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436 | * @param string $prepend |
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437 | * |
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438 | * @return array |
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439 | */ |
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440 | public function expand(array $array, $prepend = '') |
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462 | |||
463 | /** |
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464 | * Reset all numerical indexes of an array (start from zero). |
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465 | * Non-numerical indexes will stay untouched. Returns a new array. |
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466 | * |
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467 | * @param array $array |
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468 | * @param bool|false $deep |
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469 | * |
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470 | * @return array |
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471 | */ |
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472 | public function reset(array $array, $deep = false) |
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490 | |||
491 | /** |
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492 | * Extend one array with another. Non associative arrays will not be merged |
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493 | * but rather replaced. |
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494 | * |
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495 | * @param array $arrays |
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496 | * |
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497 | * @return array |
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498 | */ |
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499 | public function extendDistinct(array $arrays) |
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519 | |||
520 | /** |
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521 | * Sort the array using the given callback. |
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522 | * |
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523 | * @param array $array |
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524 | * @param callable $callback |
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525 | * @param int $options |
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526 | * @param bool $descending |
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527 | * |
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528 | * @return array |
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529 | */ |
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530 | public function sort(array $array, callable $callback, $options = SORT_REGULAR, $descending = false) |
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553 | |||
554 | /** |
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555 | * Recursively sort an array by keys and values. |
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556 | * |
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557 | * @param array $array |
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558 | * |
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559 | * @return array |
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560 | */ |
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561 | public function sortRecursive(array $array) |
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579 | |||
580 | /** |
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581 | * Will turn each element in $arr into an array then appending |
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582 | * the associated indexs from the other arrays into this array as well. |
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583 | * |
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584 | * @param array $array |
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585 | * @param array $arrays |
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586 | * |
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587 | * @return array |
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588 | */ |
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589 | public function zip(array $array, array $arrays) |
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608 | |||
609 | /** |
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610 | * Recurse through an array, add the leaf items to the $newArray var |
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611 | * |
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612 | * @param array $subject |
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613 | * @param array &$newArray |
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614 | * @param array $stack |
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615 | * |
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616 | * @return string[]|null |
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617 | */ |
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618 | private function recurseCollapse(array $subject, array &$newArray, $stack = []) |
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632 | } |
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633 |