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

Can a class in Java be abstract without containing any abstract methods?

1. Yes

2. No

3. Only if it implements an interface

4. Only in Java versions 8 and above

The correct answer is: Yes

Yes, a class in Java can be abstract without containing any abstract methods. This is because the abstract keyword in Java can also be applied to classes, which signifies that the class cannot be instantiated and must be extended by another class. This is useful when creating abstract classes that define a template for other classes to follow, but do not contain any implementation of methods. The other options, such as No, Only if it implements an interface, and Only in Java versions 8 and above, are incorrect because they do not accurately reflect the capabilities of abstract classes in Java. Option B is incorrect because abstract classes can exist without any abstract methods, as mentioned above. Option C is incorrect because implementing an interface does not make a class automatically abstract. Option D is incorrect because there is no specific version of Java that allows abstract classes without abstract methods; this has been available since the beginning of Java.