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

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Want to excel in Java? Test your knowledge with our ultimate quiz based on 'Thinking in Java'. Engage with multiple-choice questions and in-depth explanations. Boost your understanding and prepare for your exam with confidence.

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.