Sorting mixed numbers and strings with units, tens, thousands, tens of thousands etc

Question

I'm trying to get a list of strings with numbers and characters sorted. The numbers can be units tens, thousands and tens of thousands (greater possibly also).

Here's an example of the strings:

1:     abc
38:    rst
203:   pq
10371: mno
13:    defg
1023:  hi
109:   jkl

For example from list

List<string> list = new List<string>()
{
    "1:     abc",
    "38:    rst",
    "203:   pq",
    "10371: mno",
    "13:    defg",
    "1023:  hi",
    "109:   jkl",
};

My expected result would be

10371: mno
1023:  hi
203:   pq
109:   jkl
38:    rst
13:    defg
1:     abc

I've found this partial solution Sorting mixed numbers and strings

public class MixedNumbersAndStringsComparer : IComparer<string> {
    public int Compare(string x, string y) {
        double xVal, yVal;

        if(double.TryParse(x, out xVal) && double.TryParse(y, out yVal))
            return xVal.CompareTo(yVal);
        else 
            return string.Compare(x, y);
    }
}

    list.Sort(new MixedNumbersAndStringsComparer());

But it sorts it like this instead of as expected above

1:     abc
13:    defg
109:   jkl
1023:  hi
10371: mno
203:   pq
38:    rst

How would you modify the MixedNumbersAndStringsComparer class to get it to sort it as expected? Thanks!

I don't get your "it sorts like this" behavior, I get a lexicographic sort (as expected, none of the items are numbers here): https://rextester.com/RMXZU41109 — Ben Voigt, Mar 29 '22 at 20:48
Thanks @Ben Voigt for the reply. Yes it is the correct lexicographic order, but you're right I'm looking for the numeric order instead for the first 1 to 5 (or more) numeric characters of the strings. I need the strings as I've tried doing it with SortedList but I get an error of same key already present. rleffler found a good solution. Thanks again! — Lod, Mar 29 '22 at 21:03

score 1 · Accepted Answer · answered Mar 29 '22 at 20:54

I am not exactly sure about your question, but I think this is what you are looking for?

List<string> list = new List<string>()
    {
        "1:     abc",
        "38:    rst",
        "203:   pq",
        "10371: mno",
        "13:    defg",
        "1023:  hi",
        "109:   jkl",
    };

var pairedList = new List<Tuple<int, string>>();

foreach (var item in list)
{
    var items = item.Split(':');
    pairedList.Add(new Tuple<int, string>(int.Parse(items[0].Trim()), items[1]));
}

var result = pairedList.OrderByDescending(x => x.Item1).Select(x => x.Item1 + ":" + x.Item2).ToList();

Basically it is just splitting each string in the list by the : and adding the pair to a tuple. From there just order by the int value and reconstruct the list.

Perfect! Just as needed. Thank you very much! I'll study it in details and be back asa when needed. — Lod, Mar 29 '22 at 21:01

Sorting mixed numbers and strings with units, tens, thousands, tens of thousands etc

1 Answers1