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 Arrays 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 Arrays, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 11 | final class Arrays |
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| 12 | { |
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| 13 | /** |
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| 14 | * Const for lower cased array keys. |
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| 15 | * |
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| 16 | * @const integer |
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| 17 | */ |
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| 18 | const CASE_LOWER = 1; |
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| 19 | |||
| 20 | /** |
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| 21 | * Const for upper cased array keys. |
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| 22 | * |
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| 23 | * @const integer |
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| 24 | */ |
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| 25 | const CASE_UPPER = 2; |
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| 26 | |||
| 27 | /** |
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| 28 | * Const for camel caps cased array keys. |
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| 29 | * |
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| 30 | * @const integer |
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| 31 | */ |
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| 32 | const CASE_CAMEL_CAPS = 4; |
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| 33 | |||
| 34 | /** |
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| 35 | * Const for underscored cased array keys. |
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| 36 | * |
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| 37 | * @const integer |
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| 38 | */ |
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| 39 | const CASE_UNDERSCORE = 8; |
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| 40 | |||
| 41 | /** |
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| 42 | * Simply returns an array value if the key exist or null if it does not. |
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| 43 | * |
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| 44 | * @param array $array the array to be searched |
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| 45 | * @param string|integer $key the key to search for |
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| 46 | * @param mixed $default the value to return if the $key is not found in $array |
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| 47 | * |
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| 48 | * @return mixed array value or given default value |
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| 49 | */ |
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| 50 | public static function get(array $array, $key, $default = null) |
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| 54 | |||
| 55 | /** |
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| 56 | * Simply returns an array value if the key isset,4 $default if it is not |
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| 57 | * |
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| 58 | * @param array $array the array to be searched |
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| 59 | * @param string|integer $key the key to search for |
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| 60 | * @param mixed $default the value to return if the $key is not found in $array or if the value of $key element is |
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| 61 | * null |
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| 62 | * |
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| 63 | * @return mixed array value or given default value |
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| 64 | */ |
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| 65 | public static function getIfSet(array $array, $key, $default = null) |
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| 69 | |||
| 70 | /** |
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| 71 | * Sets destination array values to be the source values if the source key exist in the source array. |
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| 72 | * |
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| 73 | * @param array $source |
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| 74 | * @param array &$dest |
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| 75 | * @param array $keyMap mapping of dest keys to source keys. If $keyMap is associative, the keys will be the |
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| 76 | * destination keys. If numeric the values will be the destination keys |
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| 77 | * |
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| 78 | * @return void |
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| 79 | */ |
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| 80 | public static function copyIfKeysExist(array $source, array &$dest, array $keyMap) |
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| 87 | |||
| 88 | /** |
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| 89 | * Sets destination array values to be the source values if the source key is set in the source array. |
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| 90 | * |
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| 91 | * @param array $source |
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| 92 | * @param array &$dest |
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| 93 | * @param array $keyMap mapping of dest keys to source keys. If $keyMap is associative, the keys will be the |
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| 94 | * destination keys. If numeric the values will be the destination keys |
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| 95 | * |
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| 96 | * @return void |
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| 97 | */ |
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| 98 | public static function copyIfSet(array $source, array &$dest, array $keyMap) |
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| 105 | |||
| 106 | /** |
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| 107 | * Returns true and fills $value if $key exists in $array, otherwise fills $value with null and returns false |
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| 108 | * |
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| 109 | * @param array $array The array to pull from |
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| 110 | * @param string|integer $key The key to get |
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| 111 | * @param mixed &$value The value to set |
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| 112 | * |
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| 113 | * @return bool true if $key was found and filled in $value, false if $key was not found and $value was set to null |
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| 114 | */ |
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| 115 | public static function tryGet(array $array, $key, &$value) : bool |
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| 125 | |||
| 126 | /** |
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| 127 | * Projects values of a key into an array. |
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| 128 | * |
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| 129 | * if $input = [ |
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| 130 | * ['key 1' => 'item 1 value 1', 'key 2' => 'item 1 value 2'], |
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| 131 | * ['key 1' => 'item 2 value 1', 'key 2' => 'item 2 value 2'], |
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| 132 | * ['key 1' => 'item 3 value 1'], |
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| 133 | * ] |
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| 134 | * and $key = 'key 2' |
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| 135 | * and $strictKeyCheck = false |
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| 136 | * |
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| 137 | * then return ['item 1 value 2', 'item 2 value 2'] |
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| 138 | * |
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| 139 | * but if $strictKeyCheck = true then an InvalidArgumentException occurs since 'key 2' wasnt in item 3 |
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| 140 | * |
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| 141 | * @param array $input the array to project from |
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| 142 | * @param string|integer $key the key which values we are to project |
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| 143 | * @param boolean $strictKeyCheck ensure key is in each $input array or not |
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| 144 | * |
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| 145 | * @return array the projection |
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| 146 | * |
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| 147 | * @throws \InvalidArgumentException if a value in $input was not an array |
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| 148 | * @throws \InvalidArgumentException if a key was not in one of the $input arrays |
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| 149 | */ |
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| 150 | public static function project(array $input, $key, bool $strictKeyCheck = true) : array |
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| 166 | |||
| 167 | /** |
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| 168 | * Returns a sub set of the given $array based on the given $conditions |
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| 169 | * |
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| 170 | * @param array[] $array an array of arrays to be checked |
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| 171 | * @param array $conditions array of key/value pairs to filter by |
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| 172 | * |
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| 173 | * @return array the subset |
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| 174 | * |
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| 175 | * @throws \InvalidArgumentException if a value in $array was not an array |
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| 176 | */ |
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| 177 | public static function where(array $array, array $conditions) : array |
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| 194 | |||
| 195 | /** |
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| 196 | * Takes each item and embeds it into the destination array, returning the result. |
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| 197 | * |
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| 198 | * Each item's key is used as the key in the destination array so that keys are preserved. Each resulting item in |
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| 199 | * the destination will be embedded into a field named by $fieldName. Any items that don't have an entry in |
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| 200 | * destination already will be added, not skipped. |
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| 201 | * |
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| 202 | * For example, embedInto(['Joe', 'Sue'], 'lastName', [['firstName' => 'Billy'], ['firstName' => 'Bobby']]) will |
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| 203 | * return [['firstName' => 'Billy', 'lastName' => 'Joe'], ['firstName' => 'Bobby', 'lastName' => 'Sue']] |
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| 204 | * |
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| 205 | * @param array $items The items to embed into the result. |
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| 206 | * @param string $fieldName The name of the field to embed the items into. This field must not exist in the |
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| 207 | * destination items already. |
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| 208 | * @param array $destination An optional array of arrays to embed the items into. If this is not provided then |
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| 209 | * empty records are assumed and the new record will be created only containing |
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| 210 | * $fieldName. |
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| 211 | * @param bool $overwrite whether to overwrite $fieldName in $destination array |
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| 212 | * |
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| 213 | * @return array $destination, with all items in $items added using their keys, but underneath a nested $fieldName |
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| 214 | * key. |
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| 215 | * |
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| 216 | * @throws \InvalidArgumentException if $fieldName was not a string |
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| 217 | * @throws \InvalidArgumentException if a value in $destination was not an array |
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| 218 | * @throws \Exception if $fieldName key already exists in a $destination array |
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| 219 | */ |
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| 220 | public static function embedInto( |
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| 243 | |||
| 244 | /** |
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| 245 | * Fills the given $template array with values from the $source array |
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| 246 | * |
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| 247 | * @param array $template the array to be filled |
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| 248 | * @param array $source the array to fetch values from |
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| 249 | * |
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| 250 | * @return array Returns a filled version of $template |
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| 251 | */ |
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| 252 | public static function fillIfKeysExist(array $template, array $source) |
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| 263 | |||
| 264 | /** |
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| 265 | * Extracts an associative array from the given multi-dimensional array. |
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| 266 | * |
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| 267 | * @param array $input The multi-dimensional array. |
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| 268 | * @param string|int $keyIndex The index to be used as the key of the resulting single dimensional result array. |
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| 269 | * @param string|int $valueIndex The index to be used as the value of the resulting single dimensional result array. |
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| 270 | * If a sub array does not contain this element null will be used as the value. |
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| 271 | * @param string $duplicateBehavior Instruct how to handle duplicate resulting values, 'takeFirst', 'takeLast', |
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| 272 | * 'throw' |
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| 273 | * |
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| 274 | * @return array an associative array |
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| 275 | * |
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| 276 | * @throws \InvalidArgumentException Thrown if $input is not an multi-dimensional array |
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| 277 | * @throws \InvalidArgumentException Thrown if $keyIndex is not an int or string |
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| 278 | * @throws \InvalidArgumentException Thrown if $valueIndex is not an int or string |
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| 279 | * @throws \InvalidArgumentException Thrown if $duplicateBehavior is not 'takeFirst', 'takeLast', 'throw' |
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| 280 | * @throws \UnexpectedValueException Thrown if a $keyIndex value is not a string or integer |
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| 281 | * @throws \Exception Thrown if $duplicatedBehavior is 'throw' and duplicate entries are found. |
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| 282 | */ |
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| 283 | public static function extract( |
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| 324 | |||
| 325 | /** |
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| 326 | * Returns the first set {@see isset()} value specified by the given array of keys. |
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| 327 | * |
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| 328 | * @param array $array The array containing the possible values. |
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| 329 | * @param array $keys Array of keys to search for. The first set value will be returned. |
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| 330 | * @param mixed $default The default value to return if no set value was found in the array. |
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| 331 | * |
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| 332 | * @return mixed Returns the found set value or the given default value. |
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| 333 | */ |
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| 334 | public static function getFirstSet(array $array, array $keys, $default = null) |
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| 344 | |||
| 345 | /** |
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| 346 | * Partitions the given $input array into an array of $partitionCount sub arrays. |
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| 347 | * |
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| 348 | * This is a slight modification of the function suggested on |
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| 349 | * http://php.net/manual/en/function.array-chunk.php#75022. This method does not pad with empty partitions and |
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| 350 | * ensures positive partition count. |
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| 351 | * |
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| 352 | * @param array $input The array to partition. |
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| 353 | * @param int $partitionCount The maximum number of partitions to create. |
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| 354 | * @param bool $preserveKeys Flag to preserve numeric array indexes. Associative indexes are preserved by default. |
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| 355 | * |
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| 356 | * @return array A multi-dimensional array containing $partitionCount sub arrays. |
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| 357 | * |
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| 358 | * @throws \InvalidArgumentException Thrown if $partitionCount is not a positive integer. |
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| 359 | * @throws \InvalidArgumentException Thrown if $preserveKeys is not a boolean value. |
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| 360 | */ |
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| 361 | public static function partition(array $input, int $partitionCount, bool $preserveKeys = false) : array |
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| 380 | |||
| 381 | /** |
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| 382 | * Unsets all elements in the given $array specified by $keys |
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| 383 | * |
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| 384 | * @param array &$array The array containing the elements to unset. |
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| 385 | * @param array $keys Array of keys to unset. |
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| 386 | * |
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| 387 | * @return void |
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| 388 | */ |
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| 389 | public static function unsetAll(array &$array, array $keys) |
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| 395 | |||
| 396 | /** |
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| 397 | * Convert all empty strings or strings that contain only whitespace to null in the given array |
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| 398 | * |
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| 399 | * @param array &$array The array containing empty strings |
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| 400 | * |
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| 401 | * @return void |
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| 402 | */ |
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| 403 | public static function nullifyEmptyStrings(array &$array) |
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| 411 | |||
| 412 | /** |
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| 413 | * Traverses the given $array using the key path specified by $delimitedKey and returns the final value. |
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| 414 | * |
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| 415 | * Example: |
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| 416 | * <br /> |
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| 417 | * <pre> |
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| 418 | * use TraderInteractive\Util\Arrays; |
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| 419 | * $array = [ |
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| 420 | * 'db' => [ |
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| 421 | * 'host' => 'localhost', |
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| 422 | * 'login' => [ |
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| 423 | * 'username' => 'scott', |
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| 424 | * 'password' => 'tiger', |
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| 425 | * ], |
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| 426 | * ], |
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| 427 | * ]; |
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| 428 | * echo Arrays::getNested($array, 'db.login.username'); |
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| 429 | * </pre> |
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| 430 | * <br /> |
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| 431 | * Output: |
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| 432 | * <pre> |
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| 433 | * scott |
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| 434 | * </pre> |
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| 435 | * |
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| 436 | * @param array $array The array to traverse. |
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| 437 | * @param string $delimitedKey A string of keys to traverse into the array. |
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| 438 | * @param string $delimiter A string specifiying how the keys are delimited. The default is '.'. |
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| 439 | * |
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| 440 | * @return mixed The value at the inner most key or null if a key does not exist. |
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| 441 | */ |
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| 442 | final public static function getNested(array $array, string $delimitedKey, string $delimiter = '.') |
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| 456 | |||
| 457 | /** |
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| 458 | * Changes the case of all keys in an array. Numbered indices are left as is. |
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| 459 | * |
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| 460 | * @param array $input The array to work on. |
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| 461 | * @param integer $case The case to which the keys should be set. |
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| 462 | * |
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| 463 | * @return array Returns an array with its keys case changed. |
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| 464 | */ |
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| 465 | public static function changeKeyCase(array $input, int $case = self::CASE_LOWER) : array |
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| 485 | |||
| 486 | /** |
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| 487 | * Converts a multi-dimensional array into a single associative array whose keys are the concatinated keys |
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| 488 | * |
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| 489 | * @param array $input The array to flatten |
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| 490 | * @param string $delimiter The separator for the concatinated keys. |
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| 491 | * |
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| 492 | * @return array The flattened array |
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| 493 | */ |
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| 494 | final public static function flatten(array $input, string $delimiter = '.') : array |
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| 511 | |||
| 512 | /** |
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| 513 | * Returns all elements in the given $input array which contain the specifed $targetKey index. |
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| 514 | * |
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| 515 | * @param array $input The multi-dimensional array to check. |
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| 516 | * @param string|integer $targetKey The key to search for. |
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| 517 | * |
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| 518 | * @return array All elements of $input which contained $targetKey element with original keys preserved. |
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| 519 | */ |
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| 520 | final public static function getAllWhereKeyExists(array $input, $targetKey) : array |
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| 531 | |||
| 532 | private static function underscoreKeys(array $input) : array |
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| 543 | |||
| 544 | private static function camelCaseKeys(array $input) : array |
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| 557 | |||
| 558 | private static function ensureValidKey( |
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| 568 | |||
| 569 | private static function ensureIsArray( |
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| 570 | $value, |
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| 571 | string $message, |
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| 572 | string $exceptionClass = '\\InvalidArgumentException' |
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| 573 | ) { |
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| 574 | if (!is_array($value)) { |
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| 575 | $reflectionClass = new \ReflectionClass($exceptionClass); |
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| 576 | throw $reflectionClass->newInstanceArgs([$message]); |
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| 577 | } |
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| 578 | } |
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| 593 |