36 lines
911 B
Plaintext
36 lines
911 B
Plaintext
It is highly recommended *not* to use wildcard types as return types. Because the type inference rules are fairly complex it is unlikely the user of that API will know how to use it correctly.
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Let's take the example of method returning a "List<? extends Animal>". Is it possible on this list to add a Dog, a Cat, ... we simply don't know. And neither does the compiler, which is why it will not allow such a direct use. The use of wildcard types should be limited to method parameters.
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This rule raises an issue when a method returns a wildcard type.
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== Noncompliant Code Example
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----
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List<? extends Animal> getAnimals(){...}
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----
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== Compliant Solution
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----
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List<Animal> getAnimals(){...}
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----
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or
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----
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List<Dog> getAnimals(){...}
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----
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ifdef::env-github,rspecator-view[]
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'''
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== Comments And Links
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(visible only on this page)
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include::comments-and-links.adoc[]
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endif::env-github,rspecator-view[]
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