Q:

What would be hold some number of Double[] in java?

A List or collection or something other?
I would be storing between 10 and 20 Double[].
I would want to add more maybe, retrieve them.

A:

You mean where you could store your doubles for in-memory usage?
Go for an ArrayList.
List<Double> list = new ArrayList<Double>();
// store
list.add(10.0);
list.add(15.0);
// Retrieve
for (Double d : list) {
  System.out.println(d);
}

