Mastering Java: The Ultimate Quiz for 'Thinking in Java'

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Dive into the depths of Java with our quiz based on "Thinking in Java, Fourth Edition" by Bruce Eckel. Test your knowledge, solidify concepts, and prepare for certification with challenging questions and insightful feedback.

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

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Why can a generic class not directly inherit from its generic type parameter in Java?

Because generics in Java use type erasure
Because it causes a compilation error
Because it violates Java's type safety
Because of Java's inheritance rules

The correct answer is: Because of Java's inheritance rules

When a class extends a generic class, it must specify a concrete type for the generic parameter. In this case, if the generic class were to directly inherit from its generic type parameter, it would create a circular dependency and result in a compilation error. Additionally, this inheritance scenario would not make sense from a design standpoint as it would essentially create an infinite loop. Therefore, Java's inheritance rules prohibit a generic class from directly inheriting from its generic type parameter. Choices A and C are incorrect because generics in Java use type erasure, meaning that the generic type information is removed during compilation and replaced with Object as the type. Choice B is incorrect because it is a generic class inheriting from its generic type parameter that would cause a compilation error, not the other way around.