CompareTo issue.

[Ben Spigle]

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?

[Sijin Joseph]

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****@discussions.microsoft.com> wrote in message
news:4D**********************************@microsof t.com...

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?

[Ben Spigle]

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","1005-00","1005-00
","100500 ","100501","1005-01",
"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****@discussions.microsoft.com> wrote in message
news:4D**********************************@microsof t.com...

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?

[Sijin Joseph]

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\clr\src\classlibnative\nls\comnlsinfo .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*******@discussions.microsoft.com> wrote in message
news:BA**********************************@microsof t.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","1005-00","1005-00
","100500 ","100501","1005-01",
"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****@discussions.microsoft.com> wrote in message
news:4D**********************************@microsof t.com...

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?