Is it possible to convert integer arraylist in java to double arraylist. For example, I have;
ArrayList<Integer> array = new ArrayList<Integer>();
one example of how I am using it, is;
System.out.println(array.get(2));
but in the process of printing this out, I want to covert it into double, is it possible?
In Java 8, you can simply:
double[] arr = yourList.stream().mapToDouble(i -> i).toArray();
// now you can new ArrayList<Double>(Arrays.asList(arr))
If you work with earlier versions of Java, you can iterate on the arraylist and construct new one manually.
Double arraylist.
List<double[]>. But you don't need mapToDouble; if you want a List at the end, List<Double> list = yourList.stream().map(Double::valueOf).collect(Collectors.toList()); will do the job.If you must use Java 6/7 a simple for-loop will do the trick:
List<Integer> ints = Arrays.asList(1, 2, 3, 4);
List<Double> doubles = new ArrayList<Double>(ints.size());
for (Integer i : ints) {
doubles.add(Double.valueOf(i));
}
Or, if you simply wish to print it just assign it or cast it to a double:
double d = ints.get(0);
You can type cast int to double :
(double)array.get(2)
