How to sort an Array ArrayList?

Processing Beginners
7

FloatList is backed by an internal float[] array while the corresponding ArrayList<Float> is a Float array instead:
https://docs.Oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Float.html

The primitive float type is faster than an object Float, but nothing that big.

Here’s an example using that combo:

import java.util.List;

final List<FloatList> segs = new ArrayList<FloatList>();

for (int i = 0; i++ < 3; ) {
  final FloatList fl = new FloatList();
  segs.add(fl);
  for (int j = 0; j++ < 5; fl.append(random(-1000, 1000)));
}

for (final FloatList fl : segs)  println(fl);
println();

for (final FloatList fl : segs)  fl.sort();
for (final FloatList fl : segs)  println(fl);

exit();

And that same sketch but using a vanilla FloatList[] array instead:

final FloatList[] segs = new FloatList[3];

for (int i = 0; i < segs.length; ++i) {
  final FloatList fl = new FloatList();
  segs[i] = fl;
  for (int j = 0; j++ < 5; fl.append(random(-1000, 1000)));
}

for (final FloatList fl : segs)  println(fl);
println();

for (final FloatList fl : segs)  fl.sort();
for (final FloatList fl : segs)  println(fl);

exit();