I know that the following is case sensitive:
if (StringA == StringB) {
So is there an operator which will compare two strings in an insensitive manner?
views:
3124answers:
10
+38
A:
Try this:
string.Equals(a, b, StringComparison.CurrentCultureIgnoreCase);
John Feminella
2009-03-10 16:54:31
You should add a link, it improves the quality of answers by quite a bit.
Samuel
2009-03-10 16:55:25
I'm a relative StackOverflow newbie -- can you explain what you mean by adding a link? Do you mean to the MSDN docs?
John Feminella
2009-03-10 16:56:30
gosh you're quick .. lol I was typing the answer you got me first =D
Erick
2009-03-10 16:56:41
You can add an MSDN link (which I usually do) or if you find any interesting blog posts or such that maybe expand the answer.
Samuel
2009-03-10 17:48:14
And you could enrich your answer by trying to get close to what the asker wanted. In this case, you could post a quick extension method.
Samuel
2009-03-10 17:52:47
Such as: public static bool EqualsCaseInsensitive(this string a, string b) { return string.Equals(a, b, StringComparison.CurrentCultureIgnoreCase); }
Samuel
2009-03-10 17:55:42
If you want culture sensitive comparison, use this method. If you just want to make sure "FILE" and "file" are both accepted, use "OrdinalIgnoreCase" or your code might not work in places like Turkish locales. For more info, see http://www.moserware.com/2008/02/does-your-code-pass-turkey-test.html
Jeff Moser
2009-03-10 19:07:06
Not sure what Samuel is talking about... this answer is perfect. Its correct and self-explanatory. It needs no references. +1
Sailing Judo
2009-03-10 19:40:41
I just wonder... is this was answered in a two seconds?
Mendy
2010-04-07 02:30:25
+7
A:
System.Collections.CaseInsensitiveComparer
or
System.StringComparer.OrdinalIgnoreCase
leppie
2009-03-10 16:54:40
Where can I find more info on this. Does this mean I can use == for a case insensitive match?
GateKiller
2009-03-10 17:00:41
A:
Operator? NO, but I think you can change your culture so that string comparison is not case-sensitive.
// you'll want to change this...
System.Threading.Thread.CurrentThread.CurrentCulture
// and you'll want to custimize this
System.Globalization.CultureInfo.CompareInfo
I'm confident that it will change the way that strings are being compared by the equals operator.
John Leidegren
2009-03-10 16:55:11
Yeah, to say the very least it's utterly not what you would want to do unless you want all string comparisons to be case insensitive. But I think it changes the behavior of the equals operator.
John Leidegren
2009-03-13 11:45:42
+3
A:
string.Equals(StringA, StringB, StringComparison.CurrentCultureIgnoreCase);
Erick
2009-03-10 16:55:27
A:
if (StringA.ToUpperInvariant() == StringB.ToUpperInvariant()) {
People report ToUpperInvariant() is faster than ToLowerInvariant().
knoopx
2009-03-10 16:55:31
Invariant might be a bad idea if the current or desired culture has special rules for upper-casing.
OregonGhost
2009-03-10 16:56:50
This will also throw an exception if either (or both) strings are null.
tvanfosson
2009-03-10 17:01:49
Performance-wise, this is not such a good solution as you will create 2 new string instances here as well.
Frederik Gheysels
2009-03-13 09:48:31
A:
You can use
if (stringA.equals(StringB, StringComparison.CurrentCultureIgnoreCase))
Andy Mikula
2009-03-10 16:56:01
+1
A:
or
if (StringA.Equals(StringB, StringComparison.CurrentCultureIgnoreCase)) {
but you need to be sure that StringA is not null. So probably better tu use:
string.Equals(StringA , StringB, StringComparison.CurrentCultureIgnoreCase);
as John suggested
EDIT: corrected the bug
Grzenio
2009-03-10 16:56:45
+1
A:
There are a number of properties on the StringComparer static class that return comparers for any type of case-sensitivity you might want:
For instance, you can call
StringComparer.CurrentCultureIgnoreCase.Equals(string1, string2)
or
StringComparer.CurrentCultureIgnoreCase.Compare(string1, string2)
It's a bit cleaner than the string.Equals or string.Compare overloads that take a StringComparison argument.
Kyralessa
2009-03-10 19:09:23
+1
A:
System.StringComparer.OrdinalIgnoreCase
http://www.moserware.com/2008/02/does-your-code-pass-turkey-test.html
PoweRoy
2009-03-13 09:45:37