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 Arr 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 Arr, and based on these observations, apply Extract Interface, too.
| 1 | <?php  | 
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| 29 | class Arr  | 
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| 30 | { | 
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| 31 | /**  | 
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| 32 | * Add an element to an array using "dot" notation if it doesn't exist.  | 
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| 33 | *  | 
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| 34 | * @param array $array  | 
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| 35 | * @param string $key  | 
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| 36 | * @param mixed $value  | 
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| 37 | *  | 
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| 38 | * @return array  | 
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| 39 | */  | 
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| 40 | public static function add($array, $key, $value)  | 
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| 41 |     { | 
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| 42 |         if (is_null(static::get($array, $key))) { | 
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| 43 | static::set($array, $key, $value);  | 
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| 44 | }  | 
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| 45 | |||
| 46 | return $array;  | 
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| 47 | }  | 
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| 48 | |||
| 49 | /**  | 
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| 50 | * Build a new array using a callback.  | 
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| 51 | *  | 
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| 52 | * @param array $array  | 
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| 53 | * @param \Closure $callback  | 
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| 54 | *  | 
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| 55 | * @return array  | 
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| 56 | */  | 
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| 57 | View Code Duplication | public static function build($array, Closure $callback)  | 
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| 58 |     { | 
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| 59 | $results = [];  | 
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| 60 | |||
| 61 |         foreach ($array as $key => $value) { | 
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| 62 | list($innerKey, $innerValue) = call_user_func($callback, $key, $value);  | 
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| 63 | $results[$innerKey] = $innerValue;  | 
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| 64 | }  | 
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| 65 | |||
| 66 | return $results;  | 
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| 67 | }  | 
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| 68 | |||
| 69 | /**  | 
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| 70 | * Divide an array into two arrays. One with keys and the other with values.  | 
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| 71 | *  | 
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| 72 | * @param array $array  | 
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| 73 | *  | 
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| 74 | * @return array  | 
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| 75 | */  | 
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| 76 | public static function divide($array)  | 
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| 77 |     { | 
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| 78 | return [  | 
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| 79 | array_keys($array),  | 
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| 80 | array_values($array),  | 
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| 81 | ];  | 
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| 82 | }  | 
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| 83 | |||
| 84 | /**  | 
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| 85 | * Flatten a multi-dimensional associative array with dots.  | 
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| 86 | *  | 
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| 87 | * @param array $array  | 
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| 88 | * @param string $prepend  | 
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| 89 | *  | 
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| 90 | * @return array  | 
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| 91 | */  | 
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| 92 | public static function dot($array, $prepend = '')  | 
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| 93 |     { | 
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| 94 | $results = [];  | 
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| 95 | |||
| 96 |         foreach ($array as $key => $value) { | 
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| 97 |             if (is_array($value)) { | 
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| 98 | $results = array_merge($results, static::dot($value, $prepend.$key.'.'));  | 
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| 99 |             } else { | 
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| 100 | $results[$prepend.$key] = $value;  | 
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| 101 | }  | 
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| 102 | }  | 
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| 103 | |||
| 104 | return $results;  | 
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| 105 | }  | 
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| 106 | |||
| 107 | /**  | 
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| 108 | * Get all of the given array except for a specified array of items.  | 
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| 109 | *  | 
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| 110 | * @param array $array  | 
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| 111 | * @param array|string $keys  | 
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| 112 | *  | 
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| 113 | * @return array  | 
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| 114 | */  | 
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| 115 | public static function except($array, $keys)  | 
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| 119 | |||
| 120 | /**  | 
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| 121 | * Fetch a flattened array of a nested array element.  | 
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| 122 | *  | 
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| 123 | * @param array $array  | 
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| 124 | * @param string $key  | 
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| 125 | *  | 
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| 126 | * @return array  | 
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| 127 | */  | 
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| 128 | public static function fetch($array, $key)  | 
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| 129 |     { | 
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| 130 | $results = [];  | 
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| 131 | |||
| 132 |         foreach (explode('.', $key) as $segment) { | 
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| 133 | $results = [];  | 
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| 134 |             foreach ($array as $value) { | 
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| 135 | $value = (array) $value;  | 
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| 136 | $results[] = $value[$segment];  | 
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| 137 | }  | 
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| 138 | $array = array_values($results);  | 
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| 139 | }  | 
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| 140 | |||
| 141 | return array_values($results);  | 
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| 142 | }  | 
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| 143 | |||
| 144 | /**  | 
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| 145 | * Return the first element in an array passing a given truth test.  | 
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| 146 | *  | 
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| 147 | * @param array $array  | 
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| 148 | * @param \Closure $callback  | 
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| 149 | * @param mixed $default  | 
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| 150 | *  | 
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| 151 | * @return mixed  | 
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| 152 | */  | 
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| 153 | public static function first($array, $callback, $default = null)  | 
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| 154 |     { | 
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| 155 |         foreach ($array as $key => $value) { | 
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| 156 |             if (call_user_func($callback, $key, $value)) { | 
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| 157 | return $value;  | 
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| 158 | }  | 
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| 159 | }  | 
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| 160 | |||
| 161 | return $default;  | 
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| 162 | }  | 
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| 163 | |||
| 164 | /**  | 
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| 165 | * Return the last element in an array passing a given truth test.  | 
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| 166 | *  | 
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| 167 | * @param array $array  | 
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| 168 | * @param \Closure $callback  | 
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| 169 | * @param mixed $default  | 
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| 170 | *  | 
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| 171 | * @return mixed  | 
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| 172 | */  | 
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| 173 | public static function last($array, $callback, $default = null)  | 
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| 177 | |||
| 178 | /**  | 
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| 179 | * Flatten a multi-dimensional array into a single level.  | 
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| 180 | *  | 
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| 181 | * @param array $array  | 
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| 182 | *  | 
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| 183 | * @return array  | 
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| 184 | */  | 
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| 185 | public static function flatten($array)  | 
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| 186 |     { | 
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| 187 | $return = [];  | 
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| 188 | array_walk_recursive(  | 
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| 189 | $array,  | 
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| 190 |             function ($x) use (&$return) { | 
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| 191 | $return[] = $x;  | 
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| 192 | }  | 
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| 193 | );  | 
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| 194 | |||
| 195 | return $return;  | 
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| 196 | }  | 
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| 197 | |||
| 198 | /**  | 
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| 199 | * Remove one or many array items from a given array using "dot" notation.  | 
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| 200 | *  | 
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| 201 | * @param array $array  | 
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| 202 | * @param array|string $keys  | 
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| 203 | */  | 
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| 204 | public static function forget(&$array, $keys)  | 
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| 205 |     { | 
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| 206 | $original = &$array;  | 
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| 207 | |||
| 208 |         foreach ((array) $keys as $key) { | 
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| 209 |             $parts = explode('.', $key); | 
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| 210 |             while (count($parts) > 1) { | 
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| 211 | $part = array_shift($parts);  | 
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| 212 |                 if (isset($array[$part]) && is_array($array[$part])) { | 
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| 213 | $array = &$array[$part];  | 
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| 214 | }  | 
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| 215 | }  | 
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| 216 | unset($array[array_shift($parts)]);  | 
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| 217 | // clean up after each pass  | 
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| 218 | $array = &$original;  | 
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| 219 | }  | 
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| 220 | }  | 
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| 221 | |||
| 222 | /**  | 
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| 223 | * Get an item from an array using "dot" notation.  | 
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| 224 | *  | 
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| 225 | * @param array $array  | 
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| 226 | * @param string $key  | 
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| 227 | * @param mixed $default  | 
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| 228 | *  | 
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| 229 | * @return mixed  | 
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| 230 | */  | 
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| 231 | public static function get($array, $key, $default = null)  | 
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| 232 |     { | 
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| 233 |         if (is_null($key)) { | 
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| 234 | return $array;  | 
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| 235 | }  | 
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| 236 | |||
| 237 |         if (isset($array[$key])) { | 
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| 238 | return $array[$key];  | 
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| 239 | }  | 
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| 240 | |||
| 241 |         foreach (explode('.', $key) as $segment) { | 
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| 242 |             if (!is_array($array) || !array_key_exists($segment, $array)) { | 
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| 243 | return $default;  | 
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| 244 | }  | 
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| 245 | $array = $array[$segment];  | 
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| 246 | }  | 
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| 247 | |||
| 248 | return $array;  | 
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| 249 | }  | 
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| 250 | |||
| 251 | /**  | 
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| 252 | * Get a subset of the items from the given array.  | 
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| 253 | *  | 
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| 254 | * @param array $array  | 
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| 255 | * @param array|string $keys  | 
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| 256 | *  | 
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| 257 | * @return array  | 
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| 258 | */  | 
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| 259 | public static function only($array, $keys)  | 
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| 263 | |||
| 264 | /**  | 
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| 265 | * Pluck an array of values from an array.  | 
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| 266 | *  | 
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| 267 | * @param array $array  | 
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| 268 | * @param string $value  | 
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| 269 | * @param string $key  | 
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| 270 | *  | 
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| 271 | * @return array  | 
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| 272 | */  | 
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| 273 | public static function pluck($array, $value, $key = null)  | 
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| 292 | |||
| 293 | /**  | 
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| 294 | * Get a value from the array, and remove it.  | 
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| 295 | *  | 
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| 296 | * @param array $array  | 
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| 297 | * @param string $key  | 
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| 298 | * @param mixed $default  | 
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| 299 | *  | 
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| 300 | * @return mixed  | 
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| 301 | */  | 
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| 302 | public static function pull(&$array, $key, $default = null)  | 
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| 309 | |||
| 310 | /**  | 
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| 311 | * Set an array item to a given value using "dot" notation.  | 
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| 312 | *  | 
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| 313 | * If no key is given to the method, the entire array will be replaced.  | 
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| 314 | *  | 
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| 315 | * @param array $array  | 
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| 316 | * @param string $key  | 
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| 317 | * @param mixed $value  | 
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| 318 | *  | 
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| 319 | * @return array  | 
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| 320 | */  | 
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| 321 | public static function set(&$array, $key, $value)  | 
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| 343 | |||
| 344 | /**  | 
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| 345 | * Sort the array using the given Closure.  | 
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| 346 | *  | 
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| 347 | * @param array $array  | 
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| 348 | * @param \Closure $callback  | 
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| 349 | *  | 
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| 350 | * @return array  | 
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| 351 | */  | 
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| 352 | public static function sort($array, Closure $callback)  | 
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| 362 | |||
| 363 | /**  | 
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| 364 | * Filter the array using the given Closure.  | 
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| 365 | *  | 
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| 366 | * @param array $array  | 
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| 367 | * @param \Closure $callback  | 
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| 368 | *  | 
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| 369 | * @return array  | 
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| 370 | */  | 
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| 371 | View Code Duplication | public static function where($array, Closure $callback)  | 
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| 383 | }  | 
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| 384 |