Case-insensitive List<string>

[Mark Rae]

Hi,

Is it possible to create a case-insensitive List<string> collection?

E.g.

List<string> MyList = new List<string>;
MyList.Add("MyString");

So that:

MyList.Contains("mystring")
MyList.Contains("MyString")
MyList.Contains("MYSTRING")

all return true.

Google shows plenty of examples of how to do this with Dictionary<string,
string> collections e.g.

Dictionary<string, string> MyDictionary = new Dictionary<string,
string>(StringComparer.CurrentCultureIgnoreCase);

but I can't find an equivalent for List<string>...

Any assistance gratefully received.

Mark

 

[Nicholas Paldino [.NET/C# MVP]]

Mark,

No, the List does not support any other comparison for Contains. You
will have to use the dictionary method to determine if you have a
case-insensitive string in your set.

Hope this helps.

 

[Andreas Mueller]

Hi,

Is it possible to create a case-insensitive List<string> collection?

E.g.

List<string> MyList = new List<string>;
MyList.Add("MyString");

So that:

MyList.Contains("mystring")
MyList.Contains("MyString")
MyList.Contains("MYSTRING")

all return true.

Google shows plenty of examples of how to do this with Dictionary<string,
string> collections e.g.

Dictionary<string, string> MyDictionary = new Dictionary<string,
string>(StringComparer.CurrentCultureIgnoreCase);

but I can't find an equivalent for List<string>...

Any assistance gratefully received.

Mark

No, but you can get the information you need from a regular List<string>:

List<string> s = new List<string>();
bool contains = null != s.Find(delegate(string str)
{
return str.ToLower().Equals("MyString".ToLower());
});


HTH,
Andy

 

[Chris Taylor]

Hi,

Performing case-insensitive comparisons using ToLower/ToUpper are very
expensive, a much more efficient means is to use String.Compare. For some
non-English languages the ToLower solution is also not accurate/correct. See
my post on case-insensitive string comparisons:
http://dotnetjunkies.com/WebLog/chris.taylor/archive/2004/08/07/21393.aspx

 

[Mark Rae]

Performing case-insensitive comparisons using ToLower/ToUpper are very
expensive, a much more efficient means is to use String.Compare. For some
non-English languages the ToLower solution is also not accurate/correct.
See my post on case-insensitive string comparisons:
http://dotnetjunkies.com/WebLog/chris.taylor/archive/2004/08/07/21393.aspx

Thanks everyone.