Equals operator for zeros (BigDecimal / Double) in Java

Question

A few interesting observations w.r.t equals operator on 0 and 0.0

1. new Double(0.0).equals(0) returns false, while new Double(0.0).equals(0

Answer 1

new Double(0.0).equals(0) is actually boxed as something like this:

new Double(0.0).equals(Integer.valueOf(0))

Double.equals(...) will never return true unless given another Double instance.