Re: String.Compare seems to fail when it should not

On Tue, Sep 9, 2008 at 5:57 AM, Sébastien Lorion
<[email protected]> wrote:
> My bottom line is, if I control the data and I am 100% sure it won't contain
> problematic chars, then by all means, I will use ordinal compare and get the
> speed increase. Otherwise, as a non English native myself, I want to make my
> apps international and so, I will use the culture aware comparison (and
> other operations).

Just be careful what you use the comparison for... Note this highly
rated Connect "Won't Fix":

https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=236900

I bet this'd be a bugger of a bug to locate.

In this snippet you'd expect the two SortedLists to be identical, but
they're not, and the reason's clear -- the strings are s1<s2<s3<s1!

Dim s1 As String = "-0.67:-0.33:0.33"
Dim s2 As String = "0.67:-0.33:0.33"
Dim s3 As String = "-0.67:0.33:-0.33"
Console.WriteLine(s1.CompareTo(s2))
Console.WriteLine(s2.CompareTo(s3))
Console.WriteLine(s3.CompareTo(s1))
Dim l, m As New SortedList(Of String, Integer)
l.Add(S1,1)
l.Add(S2,2)
l.Add(S3,3)
m.Add(S3,3)
m.Add(S2,2)
m.Add(S1,1)
For Each i in m
 Console.WriteLine(i)
Next
For Each j in l
 Console.WriteLine(j)
Next

Now I know why FXCop and the built-in VS2008 Code Analysis always says
to specify the comparer and cultureinfo -- it's not just for performance!

Regards,
Mark Hurd, B.Sc.(Ma.) (Hons.)

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