Strange string sorting [duplicate]

Question

I've run into a strange sorting of string list in c#:

 var s = new List<string>();
 s.Add("as");
 s.Add("a_");
 s.Add("a0");

 s.Sort();

I was expecting this code to sort the list as:

a0
a_
as

It actually resulted in:

a_
a0
as

Can someone help me understand why a_ was sorted before a0 when the ASCII value of _ is 95 and the ASCII value of 0 is 48?

Answer 1

By default strings are sorted using CurrentCulture which uses a locale-sensitive sorting algorithm.

Use StringComparer.Ordinal to sort strings by their Unicode (not ASCII) code-points.

List<String> list = ...
list.Sort( comparer: StringComparer.Ordinal );