java upcasting polymorphism issue

Question

2 classes, A and B. class B inherits from class A. What's wrong with the following code?

B b3 = (A)(new B());

Why isn't it a legal Upcasting?

It make sense. B instructor creates the B part of the whole object then A create its part and then it acts like A.

Shoot I had a detailed answer and this was closed when I was about to post it! — ostrichofevil, Mar 23 '17 at 03:59
Just for the record: if you consider my answer helpful beyond the DUP question/answer ... feel free to accept it ;-) — GhostCat, Mar 23 '17 at 14:11

score 0 · Answer 1 · answered Mar 23 '17 at 03:52

0

Simple:

This is not legal because a B must be a B, not an A. That cast to A "invalidates" that assignment.

answered Mar 23 '17 at 03:52

GhostCat

1 Answers1