Sorting a double value of an object within an arrayList

Question

I\'m trying to sort my custom class chromosome by the value of their score attribute which is a double. These chromosomes are stored within an ArrayList. I know I have to us

Answer 1

Since java 8 you can sort list of Double elements very simple.

list.sort(Comparator.comparingDouble(Chromosome::getScore));

or

Collections.sort(list, omparator.comparingDouble(Chromosome::getScore));

If you wanna get sorted list but you don't want to change your beginning list you can do it as following:

List sortedList = list.stream()
     .sorted(Comparator.comparingDouble(A::getScore))
     .collect(Collectors.toList());