2 ms·

Class Rect { final int x, y; //Constructor goes here } Rect r1 = new Rect(1,2); Is this not sufficient to create an immutable rectangle that I can pass

• maleldil 2y ago
  When x and y are primitives, yes. But if they're objects, final only prevents you from re-assigning them. You could still call methods that mutate them.
  • loginatnine 2y ago
    Unless the object is immutable, like String, Integer, Long, ImmutableCollections, etc. Or your own immutable objects.
    • ashishb 2y ago
      > Unless the object is immutable, like String, Integer, Long, ImmutableCollections, etc. Or your own immutable objects. Exactly. You can have immutable primitives. You can have immutable classes. And you can combine them to form thread-safe immutable classes.
      • maleldil 2y ago
        Now you're restricting yourself to a subset of the language. There's nothing stopping someone from adding a mutable member to your "immutable" type later. It's much better to have immutable bindings/references so that nothing that mutates the object can be done through them. Rust does it very well, for example. Even C++ has a good version of this.
        • ashishb 2y ago
          > It's much better to have immutable bindings/references so that nothing that mutates the object can be done through them. Rust does it very well, for example. Even C++ has a good version of this. Yes, that might be superior but even Java is doing better than Go here.