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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| 10 | View Code Duplication | class Worlds |
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| 11 | { |
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| 12 | use ImmutableTrait, SerializableTrait; |
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| 13 | |||
| 14 | /** |
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| 15 | * @var int |
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| 16 | */ |
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| 17 | private $online; |
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| 18 | |||
| 19 | /** |
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| 20 | * @var array |
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| 21 | */ |
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| 22 | private $worlds; |
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| 23 | |||
| 24 | /** |
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| 25 | * Worlds constructor. |
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| 26 | * @param int $online |
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| 27 | * @param array $worlds |
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| 28 | * @throws \Igorsgm\TibiaDataApi\Exceptions\ImmutableException |
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| 29 | */ |
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| 30 | public function __construct(int $online, Collection $worlds) |
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| 37 | |||
| 38 | /** |
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| 39 | * @return int |
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| 40 | */ |
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| 41 | public function getOnline(): int |
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| 45 | |||
| 46 | /** |
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| 47 | * @return World[] |
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| 48 | */ |
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| 49 | public function getWorlds(): Collection |
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| 53 | } |
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| 54 |
Let’s assume that you have a directory layout like this:
. |-- OtherDir | |-- Bar.php | `-- Foo.php `-- SomeDir `-- Foo.phpand let’s assume the following content of
Bar.php:If both files
OtherDir/Foo.phpandSomeDir/Foo.phpare loaded in the same runtime, you will see a PHP error such as the following:PHP Fatal error: Cannot use SomeDir\Foo as Foo because the name is already in use in OtherDir/Foo.phpHowever, as
OtherDir/Foo.phpdoes not necessarily have to be loaded and the error is only triggered if it is loaded beforeOtherDir/Bar.php, this problem might go unnoticed for a while. In order to prevent this error from surfacing, you must import the namespace with a different alias: