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

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Mastering Java: The Ultimate Quiz for 'Thinking in Java'. Dive deep into Java with multiple-choice questions. Challenge yourself with quiz questions designed to test and improve your understanding of the 'Thinking in Java' book. Get ready for your exam!

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In polymorphism, what does 'upcasting' refer to?

  1. Casting an object to a more specific class

  2. Casting an object to a more general class

  3. Casting an object without changing its type

  4. Casting an object to a sibling class

The correct answer is: Casting an object to a more general class

Upcasting refers to the process of casting an object to a more general, or superclass, type. This allows the object to inherit the properties and methods of the superclass, but it may also have additional properties and methods specific to its original class. Option A is incorrect because casting an object to a more specific class is known as 'downcasting'. Option C is incorrect because it does not involve changing the type of the object at all. Option D is incorrect because casting an object to a sibling class is not possible in polymorphism, as sibling classes have different parent classes.