ToTitleCase() method is not working with Special Characters

Question

I have a string that needs to be converted such that it converts first character to Upper case. with ToTitleCase method it works fine except for the case when there is a special characters.

Below is the code and expected result

String textToConvert= "TEST^S CHECK"
TextInfo myTI = new CultureInfo("en-US",false).TextInfo;
       return myTI.ToTitleCase(textToConvert.ToLower())

Expected result: Test^s Check But the result is coming out as Test^S Check with "S" converted to capital after special character ^

Is there anyway to change th conversion to expected result

Not with `ToTitleCase`, though they do reserve the rights to make the function slower in the future ;) - for this, now, you'll have to roll your own (which should not be hard to do). — 500 - Internal Server Error, Dec 09 '19 at 11:31
What would you expect this string to become? `"TEST.S CHECK"`? — Lasse V. Karlsen, Dec 09 '19 at 11:32
Symbol `^` is called "Circumflex accent"and in Unicode is declared as "modifier symbol". In C# there is a [small static function](https://referencesource.microsoft.com/#mscorlib/system/globalization/textinfo.cs,b51cc381eb6a95dc) that determines if character is word delimiter, and modifier symbols are word delimiters. This means that the following character S is a separate word as far as .NET is concerned. — Dialecticus, Dec 09 '19 at 11:39
Just be aware that ToTitleCase is actually working just fine, it's just that what you want is not what it supports. In other words, this handling is not a bug, it's supposed to be like this. — Lasse V. Karlsen, Dec 09 '19 at 11:43

Johnathan Barclay · Accepted Answer · 2019-12-09T13:08:54.403

2

ToTitleCase is a handy method, but if you need more fine grained control, Regex might be the better option:

string titleCase = Regex.Replace(textToConvert.ToLower(), @"^[a-z]|(?<= )[a-z]",
    match => match.Value.ToUpper());

^[a-z]|(?<=\s)[a-z] will match a letter at the start of the string, and letters preceded by whitespace (space, tab or newline).

edited Dec 09 '19 at 13:08

answered Dec 09 '19 at 11:35

Johnathan Barclay

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I suggest at least `?<=\s` - preceded by *white*space (i.e., space, tab, nonbreaking space etc.) – Dmitry Bychenko Dec 09 '19 at 11:55

score 1 · Answer 2 · answered Dec 09 '19 at 11:45

Well, ToTitleCase turn 1st letter of each word to upper case while all the other to lower case. Word in terms of .Net is a consequent letters, and, alas, ^ is not a letter, that's why TEST^S consists of 2 words.

We can redefine word as

word must start from letter
word can contain letters, apostrophes ', circumflexes ^, and full stops .

In this case we can use regular expressions:

  using System.Text.RegularExpressions;

  ... 

  string source = "TEST^S CHECK по-русски (in RUSSIAN) it's a check! a.b.c.d";

  string result = Regex.Replace(source, @"\p{L}[\p{L}\^'\.]*",
    match => match.Value.Substring(0, 1).ToUpper() + match.Value.Substring(1).ToLower());

  Console.Write(result);

Outcome:

  Test^s Check По-Русски (In Russian) It's A Check! A.b.c.d

ToTitleCase() method is not working with Special Characters

2 Answers2