Replace single backslash with double backslash

Question

It seems simple enough, right? Well, I don\'t know.

Here\'s the code I\'m trying:

input = Regex.Replace(input, \"\\\\\", \"\\\\\\\\\\\\\");
         


        

Answer 1

The first one should be "\\\\", not "\\". It works like this:

• You have written "\\".
• This translates to the sequence \ in a string.
• The regex engine then reads this, which translates as backslash which isn't escaping anything, so it throws an error.

With regex, it's much easier to use a "verbatim string". In this case the verbatim string would be @"\\". When using verbatim strings you only have to consider escaping for the regex engine, as backslashes are treated literally. The second string will also be @"\\", as it will not be interpreted by the regex engine.