hy,
i've got a simple question (for somebody who already knows the answer)
about regex:
i've a string like bla@bla@bla or bla@@bla
i like to check the @'s, but couldn't figure it out how to set zero or
more char's. (zero or one was easy).
thank's
rené
Aug 6 '07
14  2263 
On Aug 7, 12:46 pm, "Kevin Spencer" <unclechut...@n othinks.comwrot e:
A string is an array of char. I believe the fastedst way would be to loop
through the chars in the string, and count the '@' chars. Once you reach 5,
you return true. If you reach the end of the string without reaching 5, you
return false.
Just to be clear: a string *isn't* an array of chars. It's a sequence
of characters, and there's a readonly indexer (as well as implementing
IEnumerable<cha r>) but it's not actually an array.
For example, you couldn't pass a string as an argument to a method
with a System.Array parameter.
Jon
On Aug 7, 10:19 am, ohmmega <sho...@gmx.atw rote:
i need this about 200 times in a time critical application, so i just
want to have the best option.
200 times in what space of time?
i've not measured the time yet, but that's a good point - i will try
this next.
That's definitely worth doing. In a little test application I wrote,
it took less than a second to check 2 *miilion* strings on my laptop.
Now, they were fairly short strings - you should test with real data -
but it's an indication.
Jon
Correct as usual, Jon. I should have said "a string encapsulates an array of
char, and can be treated just like one."
--
HTH,
Kevin Spencer
Microsoft MVP
Printing Components, Email Components,
FTP Client Classes, Enhanced Data Controls, much more.
DSI PrintManager, Miradyne Component Libraries: http://www.miradyne.net
"Jon Skeet [C# MVP]" <sk***@pobox.co mwrote in message
news:11******** *************@l 70g2000hse.goog legroups.com...
On Aug 7, 12:46 pm, "Kevin Spencer" <unclechut...@n othinks.comwrot e:
>A string is an array of char. I believe the fastedst way would be to loop
through the chars in the string, and count the '@' chars. Once you reach
5,
you return true. If you reach the end of the string without reaching 5,
you
return false.
Just to be clear: a string *isn't* an array of chars. It's a sequence
of characters, and there's a readonly indexer (as well as implementing
IEnumerable<cha r>) but it's not actually an array.
For example, you couldn't pass a string as an argument to a method
with a System.Array parameter.
Jon
On Aug 8, 12:17 pm, "Kevin Spencer" <unclechut...@n othinks.comwrot e:
Correct as usual, Jon. I should have said "a string encapsulates an array of
char, and can be treated just like one."
I think I'd still have quibbled: internally there isn't an array of
chars (unlike in Java, for instance) and you can't treat it as an
array of chars because you can always modify the contents of arrays,
whereas the string indexer is readonly.
There's always room for pedantry :)
Jon
Hi Jon,
I suppose pedantry has its place. These details are always useful to know.
In my case, I was simply talking about looping through the characters in the
string as an efficient way of counting the occurrences of a character.
However, it might have led to someone getting the wrong impression
concerning what ways one might be able to treat a string as if it were an
array of char. So, I don't take offense. I do think my solution was probably
the most efficient method for achieving the OP's goal, though. I hope that
the original problem has been solved.
--
HTH,
Kevin Spencer
Microsoft MVP
DSI PrintManager, Miradyne Component Libraries: http://www.miradyne.net
"Jon Skeet [C# MVP]" <sk***@pobox.co mwrote in message
news:11******** **************@ 57g2000hsv.goog legroups.com...
On Aug 8, 12:17 pm, "Kevin Spencer" <unclechut...@n othinks.comwrot e:
>Correct as usual, Jon. I should have said "a string encapsulates an array
of
char, and can be treated just like one."
I think I'd still have quibbled: internally there isn't an array of
chars (unlike in Java, for instance) and you can't treat it as an
array of chars because you can always modify the contents of arrays,
whereas the string indexer is readonly.
There's always room for pedantry :)
Jon
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