C# how to Regex.Replace "\r\n" (the actual characters, not the line break)

Question

I've got some horrible text that I'm cleaning up using several c# regular expressions. One issue that has me stumped is there are a number of '\r\n' strings in the text, the actual characters not the line breaks.

I've tried:

content = Regex.Replace(content, "\\r\\n", "");

and:

content = Regex.Replace(content, "\r\n", "");

but neither of them work. In the end I had to use:

content = content.Replace("\\r\\n", "\r\n");

to get the project finished, but not being able to do it in a regex annoys me.

Answer 1

\r, and \n have special meaning in Regex, too, so the backslash needs to be escaped. Then, these backslashes needs to be escaped for the c# string, leading to

content = Regex.Replace(content, "\\\\r\\\\n", ""); 

or

content = Regex.Replace(content, @"\\r\\n", ""); 

Answer 2

It is a good idea to get into the habit of using a verbatim string literals (@"example") when writing regular expressions in C#. In this case you needed this:

content = Regex.Replace(content, @"\\r\\n", "\r\n");

Otherwise you have to escape each backslash twice: once to escape it in the C# string, and then a second time to escape them for the regular expression. So a single backslash would become four backslashes with a standard string literal.