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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| 12 | class Combinations extends Combinatorics implements \Iterator |
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| 13 | { |
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| 14 | |||
| 15 | /** |
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| 16 | * The values. |
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| 17 | * |
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| 18 | * @var array |
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| 19 | */ |
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| 20 | protected $c = array(); |
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| 21 | |||
| 22 | /** |
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| 23 | * The key. |
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| 24 | * |
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| 25 | * @var int |
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| 26 | */ |
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| 27 | protected $key = 0; |
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| 28 | |||
| 29 | /** |
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| 30 | * Combinations constructor. |
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| 31 | * |
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| 32 | * @param array $dataset |
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| 33 | * The dataset. |
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| 34 | * @param int|null $length |
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| 35 | * The length. |
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| 36 | */ |
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| 37 | 10 | public function __construct(array $dataset = array(), $length = null) |
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| 42 | |||
| 43 | /** |
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| 44 | * {@inheritdoc} |
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| 45 | */ |
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| 46 | public function key() |
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| 50 | |||
| 51 | /** |
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| 52 | * {@inheritdoc} |
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| 53 | */ |
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| 54 | 4 | public function current() |
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| 55 | { |
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| 56 | 4 | $r = array(); |
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| 57 | 4 | for ($i = 0; $i < $this->length; $i++) { |
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| 58 | 4 | $r[] = $this->dataset[$this->c[$i]]; |
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| 59 | } |
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| 60 | 4 | return $r; |
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| 61 | } |
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| 62 | |||
| 63 | /** |
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| 64 | * {@inheritdoc} |
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| 65 | */ |
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| 66 | 4 | public function next() |
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| 67 | { |
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| 68 | 4 | if ($this->nextHelper()) { |
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| 69 | 3 | $this->key++; |
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| 70 | } else { |
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| 71 | 4 | $this->key = -1; |
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| 72 | } |
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| 73 | 4 | } |
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| 74 | |||
| 75 | /** |
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| 76 | * {@inheritdoc} |
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| 77 | */ |
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| 78 | 10 | public function rewind() |
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| 83 | |||
| 84 | /** |
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| 85 | * {@inheritdoc} |
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| 86 | */ |
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| 87 | 4 | public function valid() |
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| 91 | |||
| 92 | /** |
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| 93 | * Custom next() callback. |
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| 94 | * |
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| 95 | * @return bool |
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| 96 | * Return true or false. |
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| 97 | */ |
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| 98 | 4 | protected function nextHelper() |
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| 99 | { |
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| 100 | 4 | $i = $this->length - 1; |
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| 101 | 4 | while ($i >= 0 && $this->c[$i] == $this->datasetCount - $this->length + $i) { |
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| 102 | 4 | $i--; |
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| 103 | } |
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| 104 | 4 | if ($i < 0) { |
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| 105 | 4 | return false; |
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| 106 | } |
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| 107 | 3 | $this->c[$i]++; |
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| 108 | 3 | while ($i++ < $this->length - 1) { |
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| 109 | 3 | $this->c[$i] = $this->c[$i - 1] + 1; |
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| 110 | } |
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| 111 | |||
| 112 | 3 | return true; |
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| 113 | } |
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| 114 | |||
| 115 | /** |
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| 116 | * Convert the iterator into an array. |
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| 117 | * |
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| 118 | * @return array |
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| 119 | * The elements. |
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| 120 | */ |
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| 121 | 4 | View Code Duplication | public function toArray() |
| 122 | { |
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| 123 | 4 | $data = []; |
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| 124 | |||
| 125 | 4 | for ($this->rewind(); $this->valid(); $this->next()) { |
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| 126 | 4 | $data[] = $this->current(); |
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| 127 | } |
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| 128 | |||
| 129 | 4 | return $data; |
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| 130 | } |
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| 131 | |||
| 132 | /** |
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| 133 | * {@inheritdoc} |
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| 134 | */ |
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| 135 | 10 | public function count() |
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| 140 | } |
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| 141 |
Short variable names may make your code harder to understand. Variable names should be self-descriptive. This check looks for variable names who are shorter than a configured minimum.