Replace "\\" with "\" in a string in C#

c# string replace backslash
Sandeep picture Sandeep · Sep 20, 2011 · Viewed 151.3k times · Source

I still don't get how to do this. I saw many posts regarding this, but none of the solutions worked for me.

I have a string called "a\\b". The result I need is "a\b". How is this done?

I have a text file which has a database connection string pointing to an instance called - Server\DbInstance

My aim is to do a string replace in the text file -- replace "Server\DbInstance" with another value, say "10.11.12.13, 1200".

So I have:

stringToBeReplaced = @"Server\DbInstance";
newString = @"10.11.12.13, 1200";

This is where the problem starts. My stringToBeReplaced will always be "Server\\DbInstance", and when I search for this string in my text file, the search fails, as the text file doesn't have a string "Server\\DbInstance"; instead it has only "Server\DbInstance". So how do change "Server\\DbInstance" to "Server\DbInstance"?

Answer

Jon Skeet picture Jon Skeet · Sep 20, 2011

I suspect your string already actually only contains a single backslash, but you're looking at it in the debugger which is escaping it for you into a form which would be valid as a regular string literal in C#.

If print it out in the console, or in a message box, does it show with two backslashes or one?

If you actually want to replace a double backslash with a single one, it's easy to do so:

text = text.Replace(@"\\", @"\");

... but my guess is that the original doesn't contain a double backslash anyway. If this doesn't help, please give more details.

EDIT: In response to the edited question, your stringToBeReplaced only has a single backslash in. Really. Wherever you're seeing two backslashes, that viewer is escaping it. The string itself doesn't have two backslashes. Examine stringToBeReplaced.Length and count the characters.

Related questions

Replace single backslash with double backslash

It seems simple enough, right? Well, I don't know. Here's the code I'm trying: input = Regex.Replace(input, "\\", "\\\\\\"); However, I'm receiving an error, ArgumentException was unhandled - parsing "\" - Illegal \ at end of pattern. How do I do this?

Read More
How to replace part of string by position?

I have this string: ABCDEFGHIJ I need to replace from position 4 to position 5 with the string ZX It will look like this: ABCZXFGHIJ But not to use with string.replace("DE","ZX") - I need to use with position How …

Read More
C# string replace

I want to replace "," with a ; in my string. For example: Change "Text","Text","Text", to this: "Text;Text;Text", I've been trying the line.replace( ... , ... ), but can't get anything working properly.

Read More