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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What is required to add an Apple object to a List in the example provided?

  1. The List must be of type Apple

  2. The List must use a wildcard extending Apple

  3. The List must be of type Fruit

  4. Any of the listed types can be used

The correct answer is: The List must use a wildcard extending Apple

To add an Apple object to a List, the List must use a wildcard extending Apple. This is because Lists are type-specific and can only contain objects of the specified type or its subclasses. Option A is incorrect because it limits the List to only contain objects of type Apple, but not its subclasses. Option C is incorrect because it would not allow for other types of Fruit besides Apple to be added to the List. Option D is incorrect because it does not specify the type, which would result in a compilation error. Therefore, the only correct option is B, as it allows for any subclass of Apple to be added to the List.