How to form a java.util.List from double[]

Question

I'm using a function (which I don't own so can't change its return type) that returns a double[]

I'm trying to create a java.util.List<java.lang.Double> from it.

If only the function returned a Double[], then I could use Arrays.asList(...) but that doesn't work for double[].

Am I missing something simple here?

Google Guava has a helper for that - "List asList(prim... backingArray) Wraps a primitive array as a List of the corresponding wrapper type. " — Gyro Gearless, Nov 19 '15 at 08:41

score 1 · Accepted Answer · edited May 23 '17 at 12:03

1

You will unfortunately need to iterate through the entire array and create a new double[] array from scratch.

Look up boxing and unboxing to learn more about this phenomenon.

edited May 23 '17 at 12:03

Community

answered Nov 19 '15 at 08:34

jiaweizhang

score 1 · Answer 2 · answered Nov 19 '15 at 08:42

1

In Java 8 you can use streams to convert the array:

double[] d = ...;
List<Double> d2 = DoubleStream.of(d).boxed().collect(Collectors.toList());

answered Nov 19 '15 at 08:42

wero

2 Answers2