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:
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8 | abstract class AbstractVector implements VectorInterface |
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9 | { |
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10 | /** |
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11 | * @var Element[] |
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12 | */ |
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13 | protected $elements = []; |
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14 | |||
15 | /** |
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16 | * @var Matrix|null |
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17 | */ |
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18 | protected $matrix; |
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19 | |||
20 | /** |
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21 | * @var int|null |
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22 | */ |
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23 | protected $matrixOffset; |
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24 | |||
25 | /** |
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26 | * @param Element[] $elements |
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27 | * @param Matrix $matrix |
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28 | * @param int|null $matrixOffset |
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29 | */ |
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30 | 34 | public function __construct(array $elements = [], Matrix $matrix = null, $matrixOffset = null) |
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44 | |||
45 | /** |
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46 | * @param int $offset |
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47 | * |
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48 | * @return Element |
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49 | */ |
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50 | 14 | View Code Duplication | public function getElement($offset) |
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62 | /** |
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63 | * @return Element[] |
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64 | */ |
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65 | 18 | public function getElements() |
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69 | } |
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In PHP, under loose comparison (like
==
, or!=
, orswitch
conditions), values of different types might be equal.For
integer
values, zero is a special case, in particular the following results might be unexpected: