C# List Numeric Sorting

Question

I've tried a lot of methods, but I've always had problems with string expressions that are space characters. Then I came across this blog post and thought it might be useful but I do not know how to use it unfortunately. I have a list,

Edit: Game instead of Crysis, Star Citizen, 34 Games, Call of Duty. I use the game name to give an example

Game 3.1 1

Game 3.2 10

Game 3.3 11

Game 3.2 9

Game 3.18 7

Game 3.27 12

Game 3.11.2 13

Game 3.2 2

Game 3.8 5

Game 3.10 7

For Example;

        List<GameVersion> GameVersionList = new List<GameVersion>();
        GameVersionList.Add(new GameVersion() { Name = "Game 3.1", Code = "1" });
        GameVersionList.Add(new GameVersion() { Name = "Game 3.2", Code = "10" });
        GameVersionList.Add(new GameVersion() { Name = "Game 3.3", Code = "11" });
        GameVersionList.Add(new GameVersion() { Name = "Game 3.2", Code = "9" });
        GameVersionList.Add(new GameVersion() { Name = "Game 3.18", Code = "7" });
        GameVersionList.Add(new GameVersion() { Name = "Game 3.27", Code = "12" });
        GameVersionList.Add(new GameVersion() { Name = "Game 3.11.2", Code = "13" });
        GameVersionList.Add(new GameVersion() { Name = "Game 3.2", Code = "2" });
        GameVersionList.Add(new GameVersion() { Name = "Game 3.8", Code = "5" });
        GameVersionList.Add(new GameVersion() { Name = "Game 3.10", Code = "7" });

        public class GameVersion
        {
            public string Name { get; set; }
            public string Code { get; set; }
        }

It should be like that;

Game 3.1 1

Game 3.2 10

Game 3.2 9

Game 3.2 2

Game 3.3 11

Game 3.8 5

Game 3.10 7

Game 3.11.2 13

Game 3.18 7

Game 3.27 12

I want to be sorted by name. So, how to use this CompareNumeric?

        public static int CompareNumeric(this string s, string other)
    {
        if (s != null && other != null &&
            (s = s.Replace(" ", string.Empty)).Length > 0 &&
            (other = other.Replace(" ", string.Empty)).Length > 0)
        {
            int sIndex = 0, otherIndex = 0;

            while (sIndex < s.Length)
            {
                if (otherIndex >= other.Length)
                    return 1;

                if (char.IsDigit(s[sIndex]))
                {
                    if (!char.IsDigit(other[otherIndex]))
                        return -1;

                    // Compare the numbers
                    StringBuilder sBuilder = new StringBuilder(), otherBuilder = new StringBuilder();

                    while (sIndex < s.Length && char.IsDigit(s[sIndex]))
                    {
                        sBuilder.Append(s[sIndex++]);
                    }

                    while (otherIndex < other.Length && char.IsDigit(other[otherIndex]))
                    {
                        otherBuilder.Append(other[otherIndex++]);
                    }

                    long sValue = 0L, otherValue = 0L;

                    try
                    {
                        sValue = Convert.ToInt64(sBuilder.ToString());
                    }
                    catch (OverflowException) { sValue = Int64.MaxValue; }

                    try
                    {
                        otherValue = Convert.ToInt64(otherBuilder.ToString());
                    }
                    catch (OverflowException) { otherValue = Int64.MaxValue; }

                    if (sValue < otherValue)
                        return -1;
                    else if (sValue > otherValue)
                        return 1;
                }
                else if (char.IsDigit(other[otherIndex]))
                    return 1;
                else
                {
                    int difference = string.Compare(s[sIndex].ToString(), other[otherIndex].ToString(), StringComparison.InvariantCultureIgnoreCase);

                    if (difference > 0)
                        return 1;
                    else if (difference < 0)
                        return -1;

                    sIndex++;
                    otherIndex++;
                }
            }

            if (otherIndex < other.Length)
                return -1;
        }

        return 0;
    }

Answer 1

If you have game names that can consist of more than one word and possibly no version number at all, then you need to implement something a bit more complex.

We will use a class that implements IComparer<string> interface for comparing game names.

The public int Compare(string x, string y) method will:

• use Regex to split up game name into Name and Version parts
• compare names - if names are not equal, sort by name (eg Alpha vs Bravo)
• split up versions into an array using . as delimeter (eg 1.33.2 => {1, 33, 2})
• compare each (sub-)version - if a pair is not equal, sort here (eg 1.33 vs 1.32)
• if one version has a deeper sub-version level than the second, then sort using this (eg 3.2 vs 3.2.1)

class GameNameComparer : IComparer<string>
{
    static readonly Regex regx = new Regex(@"^(?<Name>.*) (?<Version>[\d\.]+)$", RegexOptions.ExplicitCapture);

    private static GameNameComparer instance;
    public static GameNameComparer Comparer
    {
        get
        {
            if (instance == null)
                instance = new GameNameComparer();
            return instance;
        }
    }

    private GameNameComparer() { }

    public int Compare(string x, string y)
    {
        var m1 = regx.Match(x);
        var m2 = regx.Match(y);

        if (m1.Success && m2.Success)
        {
            var name1 = m1.Groups["Name"].Value;
            var ver1 = m1.Groups["Version"].Value;
            var name2 = m2.Groups["Name"].Value;
            var ver2 = m2.Groups["Version"].Value;

            if (String.Equals(name1, name2, StringComparison.OrdinalIgnoreCase))
            {
                var ver1Levels = ver1.Split(new char[] { '.' });
                var ver2Levels = ver2.Split(new char[] { '.' });

                for (int i = 0; i < Math.Min(ver1Levels.Length, ver2Levels.Length); i++)
                {
                    int ver1LevelNo = 0;
                    int ver2LevelNo = 0;
                    int compare = 0;

                    if (Int32.TryParse(ver1Levels[i], out ver1LevelNo) && Int32.TryParse(ver2Levels[i], out ver2LevelNo))
                    {
                        compare = ver1LevelNo.CompareTo(ver2LevelNo);
                        if (compare != 0)
                            return compare;
                    }

                    compare = ver1Levels[i].CompareTo(ver2Levels[i]);
                    if (compare != 0)
                        return compare;
                }

                return ver1Levels.Length.CompareTo(ver2Levels.Length);
            }

            return String.Compare(name1, name2, StringComparison.OrdinalIgnoreCase);
        }

        return String.Compare(x, y, StringComparison.OrdinalIgnoreCase);
    }
}

We can now use this class to sort the game list correctly:

GameVersionList = GameVersionList.OrderBy(g=>g.Name, GameNameComparer.Comparer).ToList();

Answer 2

There's no need to add so much complexity. Using LINQ, split the Name field on Space and take last element (number). You can then use Version class to perform sorting:

var Sorted = GameVersionList.OrderBy(g => new Version(g.Name.Split(' ').Last());

If you want to sort on the name part first and then by version, change the above slightly:

var Sorted = GameVersionList.OrderBy(g => g.Name).ThenBy(g => new Version(g.Name.Split(' ').Last());

Notice how the primary sort will not (effectively) be affected by the version number

Answer 3

If every name is not the same as you commented, you can just take the substring after that space, convert it to double and sort it like

GameVersionList.OrderBy(x => double.Parse(
x.Name.Substring(
x.Name.IndexOf(' '))))

Answer 4

You can do this using the Windows API StrCmpLogicalW() to compare strings using a "natural" sort order.

You can encapsulate this in a List<T> extension:

using System.Runtime.InteropServices;

public static class ListExt
{
    [DllImport("shlwapi.dll", CharSet = CharSet.Unicode)]
    static extern int StrCmpLogicalW(string lhs, string rhs);

    public static void SortNatural<T>(this List<T> self, Func<T, string> stringSelector)
    {
        self.Sort((lhs, rhs) => StrCmpLogicalW(stringSelector(lhs), stringSelector(rhs)));
    }

    public static void SortNatural(this List<string> self)
    {
        self.Sort(StrCmpLogicalW);
    }
}

Then you can use it for your example like this:

static void Main()
{
    List<GameVersion> GameVersionList = new List<GameVersion>();
    GameVersionList.Add(new GameVersion() { Name = "Game 3.1", Code = "1" });
    GameVersionList.Add(new GameVersion() { Name = "Game 3.2", Code = "10" });
    GameVersionList.Add(new GameVersion() { Name = "Game 3.3", Code = "11" });
    GameVersionList.Add(new GameVersion() { Name = "Game 3.2", Code = "9" });
    GameVersionList.Add(new GameVersion() { Name = "Game 3.18", Code = "7" });
    GameVersionList.Add(new GameVersion() { Name = "Game 3.27", Code = "12" });
    GameVersionList.Add(new GameVersion() { Name = "Game 3.11.2", Code = "13" });
    GameVersionList.Add(new GameVersion() { Name = "Game 3.2", Code = "2" });
    GameVersionList.Add(new GameVersion() { Name = "Game 3.8", Code = "5" });
    GameVersionList.Add(new GameVersion() { Name = "Game 3.10", Code = "7" });

    GameVersionList.SortNatural(item => item.Name);

    foreach (var item in GameVersionList)
    {
        Console.WriteLine(item.Name + ": " + item.Code);
    }
}

The output is:

Game 3.1: 1
Game 3.2: 10
Game 3.2: 9
Game 3.2: 2
Game 3.3: 11
Game 3.8: 5
Game 3.10: 7
Game 3.11.2: 13
Game 3.18: 7
Game 3.27: 12

which matches your requirement.

Answer 5

You can try OrderBy Name

var sortedList = GameVersionList.OrderBy(x=>x.Name).ToList();