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

For Java methods, what is the main purpose of using the final keyword?

1. To optimize performance

2. To ensure they are not overridden

3. To make them available to subclasses

4. To enable dynamic binding

The correct answer is: To optimize performance

The final keyword serves as a way to explicitly declare that a method cannot be overridden by a subclass. This ensures that the method will behave consistently, and any attempts to modify or alter its behavior will result in an error. The option "To optimize performance" is incorrect because the final keyword does not directly affect performance. The option "To make them available to subclasses" is also incorrect because the final keyword restricts subclasses from overriding the method. The option "To enable dynamic binding" is incorrect because dynamic binding is a feature of Java that allows the program to choose the appropriate method at runtime based on the object type, and the final keyword restricts this behavior.