How does the “final” keyword in Java work? (I can still modify an object.)

Question

In Java we use final keyword with variables to specify its values are not to be changed. But I see that you can change the value in the constructor / methods of

Answer 1

You are always allowed to initialize a final variable. The compiler makes sure that you can do it only once.

Note that calling methods on an object stored in a final variable has nothing to do with the semantics of final. In other words: final is only about the reference itself, and not about the contents of the referenced object.

Java has no concept of object immutability; this is achieved by carefully designing the object, and is a far-from-trivial endeavor.