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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How can covariance be achieved with generics?

Using bounded wildcards
By directly casting List types
Through generic method arguments
Covariance is not possible with generics

The correct answer is: Using bounded wildcards

By using bounded wildcards, covariance can be achieved in generics. This allows for a specific type to be specified as the upper bound for the wildcard, allowing for the generic to only accept objects of that type or its subclasses. This allows for more flexibility and type safety when dealing with generic types. Options B and C are incorrect because they do not directly address the concept of covariance in generics. Option D is incorrect because it is possible to achieve covariance through bounded wildcards, making it a valid option.