Wrapper classes are pass by value or pass by reference?

Question

I know java is pass by reference but only for Java Objects. But why it is not applicable for Java Wrapper classes? Are Wrapper classes such as Integer, Float, Double pass by reference or pass by value? Because whenever I pass object of such classes in method and that changes some values, but outside of that method I am not getting updated Value.

Answer 1

On top of pass by value discussion, all wrapper classes in Java are immutable. They replicate the behaviour of primitives. You need to return the latest value back to see the changes.