How do I do a deep copy of a 2d array in Java?

Question

I just got bit by using .clone() on my 2d boolean array, thinking that this was a deep copy.

How can I perform a deep copy of my bool

Answer 1

I'm a fan of the Arrays utility. It has a copyOf method that will do a deep copy of a 1-D array for you, so you'd want something like this:

//say you have boolean[][] foo;
boolean[][] nv = new boolean[foo.length][foo[0].length];
for (int i = 0; i < nv.length; i++)
     nv[i] = Arrays.copyOf(foo[i], foo[i].length);