I have a situtation where CompareTo is returning strange results when having
dashes in strings. The most concise illustration is:
"10050".Compare To("1005-") = 1
"10050".Compare To("1005-0") = -1
I have run alot more tests (I can post a short program if useful), but the
rule seems to be - < 0 at the end of a string but - = 0 in the middle of a
string.
Does anybody know what's going on here?
3  1347 
When comparing strings less than and greater than are very hard to define,
the important thing we need to look at is equality.
--
Sijin Joseph http://www.indiangeek.net http://weblogs.asp.net/sjoseph
"Ben Spigle" <Ben Sp****@discussi ons.microsoft.c om> wrote in message
news:4D******** *************** ***********@mic rosoft.com... I have a situtation where CompareTo is returning strange results when
having dashes in strings. The most concise illustration is:
"10050".Compare To("1005-") = 1
"10050".Compare To("1005-0") = -1
I have run alot more tests (I can post a short program if useful), but the
rule seems to be - < 0 at the end of a string but - = 0 in the middle of a
string.
Does anybody know what's going on here?
Hmm... Maybe you can explain what's so hard about sorting strings. In 25
years in computing I have never before encountered a system that couldn't
sort a list of strings. It's a pretty basic requirement in computing.
I'm trying to sort a list to use in a binary search, where the search key
does not have to be completely specified. Here's how the list I gave it
sorted (quotation marks are just to mark the beginning/end of the key.)
"1005-","10050"," 1005-0","100500","10 05-00","1005-00
","100500 ","100501","100 5-01",
"1005-01 ","100501 ","1005-1"
Given a key of "10050" you would hope to get "10050","100500 ","100500
". With this screwed up sort, however, the algorithm would terminate when
it it saw "1005-0" so neither "100500" and "100500 " would appear in
the result list.
"Sijin Joseph" wrote: When comparing strings less than and greater than are very hard to define,
the important thing we need to look at is equality.
--
Sijin Joseph
http://www.indiangeek.net
http://weblogs.asp.net/sjoseph
"Ben Spigle" <Ben Sp****@discussi ons.microsoft.c om> wrote in message
news:4D******** *************** ***********@mic rosoft.com... I have a situtation where CompareTo is returning strange results when
having dashes in strings. The most concise illustration is:
"10050".Compare To("1005-") = 1
"10050".Compare To("1005-0") = -1
I have run alot more tests (I can post a short program if useful), but the
rule seems to be - < 0 at the end of a string but - = 0 in the middle of a
string.
Does anybody know what's going on here?
You're right, actually i was not thinking from that perspective. Anyways i
dug through the BCL code and then through Rotor, i have finally found the
code that String class in .Net uses for string comparison. It is is
\Rotor\sscli\cl r\src\classlibn ative\nls\comnl sinfo.cpp , go through the code
in this method, it sheds a lot of light on the workings of string
comparison. I haven't had the time to go through the code in detail, but
from what i see there is significant algorithm variance based on case
sensitivity, are you using a case sensitive search?
--
Sijin Joseph http://www.indiangeek.net http://weblogs.asp.net/sjoseph
"Ben Spigle" <Be*******@disc ussions.microso ft.com> wrote in message
news:BA******** *************** ***********@mic rosoft.com... Hmm... Maybe you can explain what's so hard about sorting strings. In 25
years in computing I have never before encountered a system that couldn't
sort a list of strings. It's a pretty basic requirement in computing.
I'm trying to sort a list to use in a binary search, where the search key
does not have to be completely specified. Here's how the list I gave it
sorted (quotation marks are just to mark the beginning/end of the key.)
"1005-","10050"," 1005-0","100500","10 05-00","1005-00
","100500 ","100501","100 5-01",
"1005-01 ","100501 ","1005-1"
Given a key of "10050" you would hope to get "10050","100500 ","100500
". With this screwed up sort, however, the algorithm would terminate
when it it saw "1005-0" so neither "100500" and "100500 " would appear
in the result list.
"Sijin Joseph" wrote:
When comparing strings less than and greater than are very hard to
define, the important thing we need to look at is equality.
--
Sijin Joseph
http://www.indiangeek.net
http://weblogs.asp.net/sjoseph
"Ben Spigle" <Ben Sp****@discussi ons.microsoft.c om> wrote in message
news:4D******** *************** ***********@mic rosoft.com... I have a situtation where CompareTo is returning strange results when
having dashes in strings. The most concise illustration is:
"10050".Compare To("1005-") = 1
"10050".Compare To("1005-0") = -1
I have run alot more tests (I can post a short program if useful), but
the rule seems to be - < 0 at the end of a string but - = 0 in the middle
of a string.
Does anybody know what's going on here?
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I have a situtation where CompareTo is returning strange results when having
dashes in strings. The most concise illustration is:
"10050".CompareTo("1005-") = 1
"10050".CompareTo("1005-0") = -1
I have run alot more tests (I can post a short program if useful), but the
rule seems to be - < 0 at the end of a string but - = 0 in the middle of a
string.
Does anybody know what's going on here?
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--
Jon Skeet - <skeet@pobox.com>
Web site: http://www.pobox.com/~skeet
Blog: http://www.msmvps.com/jon_skeet
C# in Depth: http://csharpindepth.com
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