Custom sort logic in OrderBy using LINQ

Question

What would be the right way to sort a list of strings where I want items starting with an underscore '_', to be at the bottom of the list, otherwise everything is alphabetical.

Right now I'm doing something like this,

autoList.OrderBy(a => a.StartsWith("_") ? "ZZZZZZ"+a : a )

Answer 1

If you want custom ordering, but don't want to supply a comparer, you can have it - sql style:

autoList
.OrderBy(a => a.StartsWith("_") ? 2 : 1 )
.ThenBy(a => a);

Answer 2

I think you need to use OrderBy(Func<>, IComparer<>) and specify your own Comparer which will implement your custom logic .

Answer 3

Use the overload of OrderBy that takes an IComparer, the first Func argument will feed the comparer, and from there you need to compare the strings. First deal with the case of one or both starts with _, and then from there you will probably need to strip the _ and just use the standard string.Compare to sort them beyond the first _