.NET method to convert a string to sentence case

by

There isn’t anything built in to .NET – however, this is one of those cases where regular expression processing actually may work well. I would start by first converting the entire string to lower case, and then, as a first approximation, you could use regex to find all sequences like [a-z]\.\s+(.), and use ToUpper() to convert the captured group to upper case. The RegEx class has an overloaded Replace() method which accepts a MatchEvaluator delegate, which allows you to define how to replace the matched value.

Here’s a code example of this at work:

var sourcestring = "THIS IS A GROUP. OF CAPITALIZED. LETTERS.";
// start by converting entire string to lower case
var lowerCase = sourcestring.ToLower();
// matches the first sentence of a string, as well as subsequent sentences
var r = new Regex(@"(^[a-z])|\.\s+(.)", RegexOptions.ExplicitCapture);
// MatchEvaluator delegate defines replacement of setence starts to uppercase
var result = r.Replace(lowerCase, s => s.Value.ToUpper());

// result is: "This is a group. Of uncapitalized. Letters."

This could be refined in a number of different ways to better match a broader variety of sentence patterns (not just those ending in a letter+period).

More Related Contents:

  1. What is the difference between String and string in C#?
  2. Why .NET String is immutable? [duplicate]
  3. Escape double quotes in a string
  4. What is the difference between String and string in C#?
  5. Why would you use String.Equals over ==? [duplicate]
  6. Efficient way to remove ALL whitespace from String?
  7. How do I write a backslash (\) in a string?
  8. Comparing two strings, ignoring case in C# [duplicate]
  9. Splitting a string / number every Nth Character / Number?
  10. Is String.Contains() faster than String.IndexOf()?
  11. Java equivalents of C# String.Format() and String.Join()
  12. Need to perform Wildcard (*,?, etc) search on a string using Regex
  13. string.IsNullOrEmpty(string) vs. string.IsNullOrWhiteSpace(string)
  14. How to split a number into individual digits in c#? [duplicate]
  15. @(at) sign in file path/string [duplicate]
  16. C# equivalent to Java’s charAt()?
  17. How to capitalize the first character of each word, or the first character of a whole string, with C#?
  18. What is the correct way to compare char ignoring case?
  19. Convert XmlDocument to String
  20. How do I get the last four characters from a string in C#?
  21. String Interpolation vs String.Format
  22. Open a file and replace strings in C#
  23. Why does .ToString() on a null string cause a null error, when .ToString() works fine on a nullable int with null value?
  24. Does String.GetHashCode consider the full string or only part of it?
  25. How to check if a String contains any letter from a to z? [duplicate]
  26. Fastest way to check if string contains only digits in C#
  27. Does C# have a String Tokenizer like Java’s?
  28. Convert String^ in c# to CString in c++/CLI
  29. Parsing formatted string
  30. Parsing through Arabic / RTL text from left to right

Leave a Comment