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 might you use List<? extends Object> instead of List<?>?

To clarify that objects in the List extend Object
To allow addition of any object type to the List
There is no practical use; they mean the same thing
To differentiate from raw types in method signatures

The correct answer is: There is no practical use; they mean the same thing

List<?> and List<? extends Object> essentially have the same meaning, as both are wildcard types that can store any type of objects. Therefore, there is no practical difference in using one over the other. Option A is incorrect because the keyword "extends" is not necessary when using the wildcard "?". Option B is incorrect as both options allow for the addition of any object type to the list. Option D is incorrect because the usage of wildcard types is not related to differentiating from raw types in method signatures.