What does it imply when a class is declared as final?

• A. It cannot be instantiated directly
• B. It cannot be inherited by subclasses
• C. It can only have final fields
• D. It must contain abstract methods

Answer: (B)

When a class is declared as final, it means that the class cannot be inherited by any subclasses. This is particularly useful in scenarios where you want to protect the integrity of a class and prevent alteration of its behavior through inheritance. By marking a class as final, it ensures that subclasses cannot introduce changes that could affect how the class operates.

For instance, if you designed a security-related class that should not be extended or altered in any way, declaring it as final would enforce this restriction, thus maintaining its intended functionality.

The other options suggest misconceptions about the declaration of final classes. A final class can still be instantiated directly, can have non-final fields, and does not require it to contain abstract methods at all. In fact, it’s common for a final class to provide complete implementations without leaving any methods abstract.