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 are wrapper classes used in Java generics?

To allow primitive types as type parameters
For type safety and elimination of casts
To enhance performance
To enable collections to work with primitives

The correct answer is: To allow primitive types as type parameters

Wrapper classes are used in Java generics to allow primitive types as type parameters. This is because generics only accept objects as type parameters, so primitive types cannot be used directly. Wrapper classes, such as Integer and Double, wrap around the primitive types and allow them to be used in generics. Additionally, using primitive types in generics would result in auto-boxing and unboxing, which can cause performance issues. Therefore, options B, C, and D are incorrect as they either do not mention the main purpose of wrapper classes in generics or they suggest incorrect reasons for using them.