Is it possible for an abstract class to exist without any abstract methods?

• A. Yes, it can exist without abstract methods
• B. No, it must have at least one abstract method
• C. Only if it implements an interface
• D. Not applicable in object-oriented programming

Answer: (A)

An abstract class can indeed exist without any abstract methods. In Java, the primary purpose of declaring a class as abstract is to prevent it from being instantiated directly. This means that an abstract class may still contain concrete methods (methods with implementations) and fields, while serving as a base class for other subclasses.

By having an abstract class without abstract methods, you can still provide a common structure or functionality that can be shared among its subclasses. This might include shared state or actual implementations of methods that subclasses can use or override.

The other choices suggest limitations or conditions around abstract classes that aren't accurate in Java. Abstract classes provide flexibility in how they are used, allowing for a design where shared behavior, even without abstract methods, can encapsulate common functionality applicable to derived classes.