Sort array of objects in Processing Javascript mode

I'm building a little game in Processing's Javascript mode and have my enemies as objects in an array. I'd like to sort them by their Y coordinate to draw them in vertical order (and not overlap and look weird). Since they are generated and respawned over the course of the game, I need to sort this array repeatedly.

I've done this before in the regular Java mode using Arrays.sort() and Comparable, but that doesn't work in JS mode.

Any ideas? I found this suggestion but can't figure out how to implement it:

enemies.sort(function(a,b) { return parseFloat(a.yPos) - parseFloat(b.yPos) } );

EDIT
As requested, here's a bit more context:

Enemy[] enemies = new Enemy[10];

void setup() {
  for (int i=0; i<10; i++) {
    enemies[i] = new Enemy();
  }
  enemies.sort(function(a,b) { return parseFloat(a.yPos) - parseFloat(b.yPos) } );
}

class Enemy {
  float xPos, yPos;

  Enemy() {
    xPos = random(0,width);
    yPos = random(0,height);
  }
}

This throws an error on the sort line: unexpected token: {.

I know one can mix pure JS within Processing JS, but in this case it doesn't work and I don't know why.