Error in Bukkit.getOnlinePlayers()

What am I doing wrong?
Error in: int j = (arrayOfPlayer = Bukkit.getOnlinePlayers()).length;

Code (Text):

 private static List<Player> getPlayers(Location center, double range)
  {
    List<Player> players = new ArrayList();
    String name = center.getWorld().getName();
    double squared = range * range;
    Player[] arrayOfPlayer;
    int j = (arrayOfPlayer = Bukkit.getOnlinePlayers()).length;
    for (int i = 0; i < j; i++)
    {
      Player p = arrayOfPlayer[i];
      if ((p.getWorld().getName().equals(name)) && (p.getLocation().distanceSquared(center) <= squared)) {
        players.add(p);
      }
    }
    return players;
  }

 

I am learning.