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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9 | final class ConnectorFactory |
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10 | { |
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11 | /** |
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12 | * @param array $config |
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13 | * |
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14 | * @return Connector |
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15 | * |
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16 | * @throws InvalidArgumentException |
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17 | */ |
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18 | 2 | public function create(array $config) |
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34 | |||
35 | /** |
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36 | * @param array $config |
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37 | * |
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38 | * @return array |
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39 | * |
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40 | * @throws InvalidArgumentException |
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41 | */ |
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42 | 2 | private function validate(array $config) |
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62 | } |
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63 |
If you define a variable conditionally, it can happen that it is not defined for all execution paths.
Let’s take a look at an example:
In the above example, the variable $x is defined if you pass “foo” or “bar” as argument for $a. However, since the switch statement has no default case statement, if you pass any other value, the variable $x would be undefined.
Available Fixes
Check for existence of the variable explicitly:
Define a default value for the variable:
Add a value for the missing path: