Java Comparator.comparing not comparing?

Question

Following this question about sorting a list by another list, I tried to do the same thing - but from some reason it doesn\'t work for me. What am I missing?

Answer 1

You can make a list of pairs :

[3.0, 5.0]
[1.0, 0.9]
[2.0, 10.4]

Then sort this list of pairs by the first value of each array :

[1.0, 0.9]
[2.0, 10.4]
[3.0, 5.0]

Here is the code :

List nums = Arrays.asList(5.0, 0.9, 10.4);
List order = Arrays.asList(3.0, 1.0, 2.0);

List pairs = new ArrayList<>();
for (int i = 0; i < nums.size(); i++) {
    pairs.add(new Double[] {order.get(i), nums.get(i)});
}

pairs.sort(Comparator.comparing(pair -> pair[0]));

for (Double[] pair : pairs) {
    System.out.print(pair[1] + " ");
}

Output :

0.9 10.4 5.0