Natural Sorting in LINQ

Question

 SortedList = List.OrderBy(object1=> object1.Order.Split(';')[0])
                        .ThenBy(object2=> object2.Order.Split(';')[1])
                        .ThenBy(object3=> object3.Order.Split(';')[2])
                        .ToList();

Order has a Value off 1;1;1. I Split at ";" and sort the Elements. But i get a "alphabetical Order". That means 1,10,2,3. String Format to 4 Digits is not possible because the object is not a String. Is a natural Order possible in LINQ?

https://stackoverflow.com/questions/248603/natural-sort-order-in-c-sharp — Dmitry Bychenko, Nov 06 '18 at 13:41
Possible duplicate of [Natural Sort Order in C#](https://stackoverflow.com/questions/248603/natural-sort-order-in-c-sharp) — horotab, Nov 06 '18 at 13:45
You could Select() to tuple (obj, int s0, int s1, int s2) and then order by the ints. — Christoph Lütjen, Nov 06 '18 at 13:45

score 3 · Accepted Answer · answered Nov 06 '18 at 14:10

Are you certain that every Object.Order is a colon separated string of at least 3 integer values?

Why not convert these three values to integer and sort by the parsed values?

var result = myInputSequence.Select(sourceItem => new
{

    SplitOrderNumbers = (sourceItem.Order.Split(';')
        .Select(splitItem => Int32.Parse(splitItem))
        .Take(3)
        .ToList(),
    OriginalSourceItem = sourceItem,
})
.OrderBy(item => item.SplitOrderNumbers[0])
.ThenBy(item => item.SplitOrderNumbers[1])
.ThenBy(item => item.SplitOrderNumbers[2])
.Select(item => item.OriginalSourceItem);

Bonus point: unlike in your solution, you split your orders only once.

I was about to post this minus the single split. I humbly retract and upvote for your better answer. — Broom, Nov 06 '18 at 14:13
Technically speaking I think the underlying quicksort algorithm is gonna re-issue those split operations — Malachi, Nov 06 '18 at 14:39

Malachi · Answer 2 · 2018-11-06T14:37:41.267

You can customize ordering behavior to your needs by implementing IComparer. See: Microsoft Documentation. That said, I like Harald Coppoolse's answer better. In fact, I like his answer so much I like it in linq syntax too:

var result = from n in myInputSequence
                let split = n.Order.Split(';').
                    Select(splitItem => Int32.Parse(splitItem)).
                    Take(3).ToList()
                orderby split[0], split[1], split[2]
                select n;

Natural Sorting in LINQ

2 Answers2