对包含浮点数的字符串列表进行排序

Question

I have a list of object which contains a field Number. This field is a string that includes float numbers: 0.5, 0.2, 10.0, 2.2, 2.1, 1.1, 1.0, 2.12, 1.14. I want this list sorted (descendent) based on this Number so I have this output: 10.0, 2.2, 2.12, 2.1, 1.14, 1.1, 1.0, 0.5, 0.2.

I have tried to do this:

List<MyObject> sortedList = myUnsortedList.OrderyDescending(x => x.Number).ToList();

Also, I have tried to use PadLeft like this (as this user suggested https://stackoverflow.com/a/6396523/3872144 ):

int maxlen = myUnsortedList.Max(x => x.Number.Length);

List<MyObject> sortedList = myUnsortedList.OrderyDescending(x => x.Number.PadLeft(maxlen, '0'));

But in both cases I got wrong results like: 2.12, 10.0, 2.2, 2.1, 1.14, 1.1, 1.0, 0.5, 0.2.

Do you have any idea how to solve this issue?

Answer 1

The question arises why you have a string in the first place if you store a double . You should parse them as soon as possible (or prevent that they are strings where you load them).

However, you can always try to parse them afterwards:

List<MyObject> sortedList = myUnsortedList
    .OrderyDescending(x => double.Parse(x.Number))
    .ToList();

If you dont know if they have all a valid format you can use double.TryParse . Maybe you need to pass the appropriate CultureInfo to double.Parse (for example if your current culture uses comma as decimal separator).