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

Can inner classes be declared private or protected?

1. Yes

2. No

3. Only private

4. Only protected

The correct answer is: Yes

Inner classes can be declared with any access modifier, including private and protected. However, it is common practice to declare inner classes as private so that they cannot be accessed or instantiated by other classes. Protected inner classes can be accessed by subclasses, but it is not commonly used. Therefore, options B, C, and D are incorrect as they imply that inner classes cannot have certain access modifiers. The correct answer is option A, as it acknowledges that inner classes can be declared with any access modifier.