How to cast from List to double[] in Java?

Question

I have a variable like that:

List frameList =  new ArrayList();

/* Double elements has added to frameList */

H

Answer 1

As per your question,

List frameList =  new ArrayList();

1. First you have to convert List to Double[] by using

   Double[] array = frameList.toArray(new Double[frameList.size()]);
   

2. Next you can convert Double[] to double[] using

   double[] doubleArray = ArrayUtils.toPrimitive(array);
   

You can directly use it in one line:

double[] array = ArrayUtils.toPrimitive(frameList.toArray(new Double[frameList.size()]));