How can I sort a segmented string according to level using linq?

Question

Is it possible to sort a list of segmented string according to their level and alphabetically using linq?

For example-

Given List

System
System.Collection.Generic
System.Generic
System.Linq
System.Linq.Collection.Generic

Sorted List

System
System.Generic
System.Linq
System.Collection.Generic
System.Linq.Collection.Generic

I think you could do this with a custom iComparable. http://stackoverflow.com/questions/985657/use-own-icomparert-with-linq-orderby — paparazzo, Mar 09 '17 at 16:35
Have you even tried *anything* to achieve this? Or should we do your work? — MakePeaceGreatAgain, Mar 09 '17 at 16:36

score 3 · Accepted Answer · answered Mar 09 '17 at 16:41

3

You can order by the number of . in each string:

var sortedItems = items
    // Order by number of periods ("levels")
    .OrderBy(x => x.Count(c => c == '.'))

    // Then everything else alphabetically
    .ThenBy(x => x);

Here's a fiddle to demonstrate: https://dotnetfiddle.net/FivBPA

answered Mar 09 '17 at 16:41

Nate Barbettini

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This is better than my answer as it doesn't rely on splitting the string – TheLethalCoder Mar 09 '17 at 16:42
@TheLethalCoder I upvoted yours anyway, since you beat me to it. :) – Nate Barbettini Mar 09 '17 at 16:42

score 1 · Answer 2 · edited May 23 '17 at 10:30

I think you just need to order by number or parts and then a normal alphabetical order:

var result = list.OrderBy(s => s.Split('.').Length).ThenBy(s => s);

A better (and probably faster) way to do it would be to count the number of .s in the string instead of splitting on them (idea taken from this answer by @NateBarbettini):

var result = list.OrderBy(s => s.Count(c => c == '.')).ThenBy(s => s);

score 0 · Answer 3 · answered Mar 09 '17 at 16:41

You can user OrderBy() with Count().

Demo on .NetFiddle

using System;
using System.Linq;


public class Program
{
    public static void Main()
    {
        var k = @"System
System.Collection.Generic
System.Generic
System.Linq
System.Linq.Collection.Generic";

        // We split by new line, then order them by occurrence count of '.'
        var ordered = k.Split('\n').OrderBy(x => x.Count(l => l == '.'))

        foreach (var item in ordered)
            Console.WriteLine(item);
    }
}

output

System
System.Generic
System.Linq
System.Collection.Generic
System.Linq.Collection.Generic

How can I sort a segmented string according to level using linq?

3 Answers3