Getting back primitive array after insertion into an ArrayList of primitive arrays in Java

Question

List x = new ArrayList();
x.add(new double[]={1,2,3,4,54,6});  

elements 1,2,3,4,54,6 are added to x

Answer 1

The default toString() implementation of any Object (including the double[]) is the return of the Object address. This is what it is printed by your code.