there are possibilities:
1000 -> 1000
10.000 -> 10 (without point in result)
10.0100 -> 10.01
10.1234 -> 10.1234
I am lazy and stupid, just
s = s.indexOf(".") < 0 ? s : s.replaceAll("0*$", "").replaceAll("\\.$", "");
Same solution using contains
instead of indexOf
as mentioned in some of the comments for easy understanding
s = s.contains(".") ? s.replaceAll("0*$","").replaceAll("\\.$","") : s