Based on my previous question, I've trying now to have them in the following order using the same approach, OrderByDescending and ThenBy
Original (can be in any random order):
1:1
0:0
0:1
2:1
1:0
2:0
Output
2:0
1:0
0:0
2:1
1:1
0:1
as you can see, a is descending, and b being ascending. But I'm still not getting the right sort. Any ideas why? Thanks
Think to what you would do manually:
Translated in LINQ it's pretty the same:
var sorted = arrayList
.Cast<string>()
.Select(x => x.Split(':'))
.OrderBy(x => x[1])
.ThenByDescending(x => x[0])
.Select(x => x[0] + ":" + x[1]);
To clarify a bit more, ThenBy/ThenByDescending methods are used to sort elements that are equal in the previous OrderBy/OrderByDescending, hence the code :)
Aggregate() is similar to Sum(), it transforms a list to a single element. Here we want a list, we just need to change each element into something else (i.e. projection) and Select() is the right method to use in case of projection :)Select(x => x.Aggregate((l, h) => l + ":" + h)); yes, you can also use that even if I prefer string.Join for strings. Anyway, in this case there are just 2 little strings then a simple concatenation is more readable IMO.string.Join() doesn't add the separator after the last field. For string joining Aggregate() and string.Join() give the same results, peraphs string.Join is better because it uses less memory using a StringBuilder under the hood and IMO is more readable :)arrayList.ToList().Select(i => { var split = i.Split(":".ToArray(),2));
return new { a = Int32.Parse(split[0]),
b = Int32.Parse(split[1}) };
})
.OrderByDescending(i => i.a)
.ThenBy(i => i.b)
From your question it is not clear whether you want the order-by's reversed (just swap them). Work from there, perhaps rejoining
.Select(i => String.Format("{0}:{1}", i.a, i.b));
Good luck
List<string>notArrayList