Comparing doubles in Java gives odd results

Question

I really can\'get my head around why the following happens:

Double d = 0.0;
System.out.println(d == 0); // is true
System.out.println(d.equals(0)); // is false ?         


        

Answer 1

When you perform

d == 0

this is upcast to

d == 0.0

however there are no upcasting rules for autoboxing and even if there were equals(Object) gives no hits that you want a Double instead of an Integer.