What does the 'final' keyword do to a class field?

What does the 'final' keyword do to a class field?

• A. Prevents reassignment after initialization (makes it a constant)
• B. Makes the field publicly accessible
• C. Allows the field to be changed only within the class
• D. Ensures the field is synchronized

Answer: (A)

The final keyword on a class field means the value cannot be reassigned after it has been initialized. For primitive types, that value is fixed; for object references, the reference cannot change to point to another object, though the object’s internal state can still be modified if the object itself is mutable. This is why final fields act like constants once initialized, typically assigned either at declaration or in the constructor for instance fields. It does not control access (public/private), nor does it guarantee thread-safety or synchronization.