How to replace line breaks in a string in C#?

In C#, you often need to remove or replace line breaks from strings when processing text data. Line breaks can appear as
(line feed), \r (carriage return), or \r
(Windows-style line endings). This article demonstrates different approaches to handle line breaks in strings.

Common Line Break Characters

Different operating systems use different line break characters −

• 
− Line Feed (LF), used on Unix/Linux/Mac

• \r − Carriage Return (CR), used on older Mac systems

• \r
− Carriage Return + Line Feed (CRLF), used on Windows

Windows \r
Old Mac \r

Using String.Replace() Method

The Replace() method is the simplest approach to replace specific line break sequences −

Example

using System;

class Program {
   static void Main(string[] args) {
      string testString = "Hello \r<br> beautiful <br>\t world";
      Console.WriteLine("Original: " + testString.Replace("\r", "\r").Replace("<br>", "\<br>").Replace("\t", "\t"));
      
      string replacedValue = testString.Replace("\r<br>", "_").Replace("<br>", "_").Replace("\r", "_");
      Console.WriteLine("Replaced: " + replacedValue);
   }
}

The output of the above code is −

Original: Hello \r<br> beautiful <br>\t world
Replaced: Hello _ beautiful _	 world

Using Regular Expressions

Regular expressions provide a more flexible approach to handle multiple line break patterns at once −

Example

using System;
using System.Text.RegularExpressions;

class Program {
   static void Main(string[] args) {
      string testString = "Hello \r<br> beautiful <br> world \r end";
      Console.WriteLine("Original: " + testString.Replace("\r", "\r").Replace("<br>", "\<br>"));
      
      string replacedValue = Regex.Replace(testString, @"\r<br>|\r|<br>", " ");
      Console.WriteLine("Replaced: " + replacedValue);
   }
}

The output of the above code is −

Original: Hello \r<br> beautiful <br> world \r end
Replaced: Hello  beautiful  world  end

Using Environment.NewLine

For platform-specific line breaks, use Environment.NewLine to handle the current system's line ending −

Example

using System;

class Program {
   static void Main(string[] args) {
      string multilineText = "Line 1" + Environment.NewLine + "Line 2" + Environment.NewLine + "Line 3";
      Console.WriteLine("Original:");
      Console.WriteLine(multilineText);
      
      string singleLine = multilineText.Replace(Environment.NewLine, " | ");
      Console.WriteLine("\nReplaced:");
      Console.WriteLine(singleLine);
   }
}

The output of the above code is −

Original:
Line 1
Line 2
Line 3

Replaced:
Line 1 | Line 2 | Line 3

Comparison of Methods

Conclusion

Replacing line breaks in C# strings can be accomplished using String.Replace() for simple cases, Regex.Replace() for complex patterns, or Environment.NewLine for platform-specific handling. Choose the method that best fits your specific requirements and performance needs.