How to compare strings with case insensitive and without accents

Question

How to compare strings with case insensitive and without accent

Good thing this is easily done on SQL Server

However, I would like to do the same in C # .NET 4.5.1.

How can I do this in the best way?

I mean, these 3 lines should return equal when comparing

http://www.buroteknik.com/metylan-c387c4b0ft-tarafli-bant-12cm-x25mt_154202.html http://www.buroteknik.com/METYLAN-C387C4B0FT-TARAFLI-BANT-12cm-x25mt_154202.html http://www.buroteknik.com/METYLAN-C387C4B0FT-TARAFLı-BANT-12cm-x25mt_154202.html 

I need a method that would say that the 2 below are similar to the same SQL server that they are equal.

  tarafli TARAFLİ 

Answer 1

To ignore both case and arguments, you can use string.Compare() with IgnoreNonSpace and IgnoreCase , for example:

 string s1 = "http://www.buroteknik.com/metylan-c387c4b0ft-tarafli-bant-12cm-x25mt_154202.html"; string s2 = "http://www.buroteknik.com/METYLAN-C387C4B0FT-TARAFLI-BANT-12cm-x25mt_154202.html"; string s3 = "http://www.buroteknik.com/METYLAN-C387C4B0FT-TARAFLı-BANT-12cm-x25mt_154202.html"; Console.WriteLine(string.Compare(s1, s2, CultureInfo.CurrentCulture, CompareOptions.IgnoreNonSpace | CompareOptions.IgnoreCase)); Console.WriteLine(string.Compare(s2, s3, CultureInfo.CurrentCulture, CompareOptions.IgnoreNonSpace | CompareOptions.IgnoreCase)); 

In response to your comments below, this works for tarafli and TARAFLİ .

The following code prints 0, meaning the lines are equal :

 string s1 = "tarafli"; string s2 = "TARAFLİ"; Console.WriteLine(string.Compare(s1, s2, CultureInfo.CurrentCulture, CompareOptions.IgnoreNonSpace | CompareOptions.IgnoreCase)); 

And here he uses Turkish culture (I guess what the right culture is). This also prints 0:

 string s1 = "tarafli"; string s2 = "TARAFLİ"; var trlocale = CultureInfo.GetCultureInfo("tr-TR"); Console.WriteLine(string.Compare(s1, s2, trlocale, CompareOptions.IgnoreNonSpace | CompareOptions.IgnoreCase)); 

Answer 2

You can use string.Compare with an overload that accepts the correct CultureInfo and CompareOptions :

 string.Compare(s1, s2, CultureInfo.CurrentCulture, CompareOptions.IgnoreNonSpace | CompareOptions.IgnoreCase); 

Edit:

Regarding your question about CultureInfo , from MSDN :

The comparison uses a culture parameter to obtain culture-specific information, such as casing rules and alphabetical order of individual characters. For example, a particular culture may indicate that certain combinations of characters are treated as a single character, so that upper and lower case characters are compared in a special way, or that the character's sort order depends on the characters that precede or follow it.