Replace \\ with \ in C#

Question

I have a long string (a path) with double backslashes, and I want to replace it with single backslashes:

string a = "a\\b\\c\\d";
string b = a.Replace(@"\\", @"\");

This code does nothing...

b remains "a\\b\\c\\d"

I also tried different combinations of backslashes instead of using @, but no luck.

You should use Path.Combine for file paths anyway.. also, can I ask why? — Sayse, Jul 29 '13 at 07:18
@Corak, I don't create a, I get it from somewhere else.. it just looks like a\\b\\c\\d — user990635, Jul 29 '13 at 07:20
Exactly. It *looks* like it has two backslashes. Try `Console.WriteLine("a\\b")` and the second backslash magically disappeares. — Corak, Jul 29 '13 at 07:21
The variable containing this string has two, therefore it crushes later on — user990635, Jul 29 '13 at 07:22
["By default the debugger will display backslash characters as double backslashes since it's using the backslash as a control character."](http://graperblog.blogspot.co.uk/2008/03/visual-studio-2005-debugger-irritation.html) - Is this what you are seeing? — Sayse, Jul 29 '13 at 07:23
Okay, if `var a = @"a\\b";` (note the `@`), then `var b = a.Replace(@"\\", @"\");` should already get rid of the second backslash. Be sure the strings are what you think they are. — Corak, Jul 29 '13 at 07:25

score 8 · Answer 1 · answered Jul 29 '13 at 07:21

8

Because you declared a without using @, the string a does not contain any double-slashes in your example. In fact, in your example, a == "a\b\c\d", so Replace does not find anything to replace. Try:

string a = @"a\\b\\c\\d";
string b = a.Replace(@"\\", @"\");

answered Jul 29 '13 at 07:21

Otiel

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I didn't declare a. I showed it here as an example. I get it like that from somewhere else – user990635 Jul 29 '13 at 07:23
1

So your example is wrong and misleading then, thus we can't answer your question. Are you sure your string "*from somewhere else*" does actually contain double-slashes? – Otiel Jul 29 '13 at 07:24
1

@user990635: Still: Your Replace statement is correct. It *does* remove double backslashes if there are any. Try to output `b` with `Console.WriteLine` to see for yourself. – Heinzi Jul 29 '13 at 07:24
@user990635 - please be careful on what your string variable really containes. And be aware that `"a\\b"` is *NOT* the same as `@"a\\b"`. In fact, as I already mentioned, `"a\\b"` is *the same* as `@"a\b"`. – Corak Jul 29 '13 at 07:30

score 1 · Answer 2 · answered Jul 29 '13 at 07:24

You're wrong. "\\" return \ (know as escaping)

string a = "a\\b\\c\\d";
System.Console.WriteLine(a);  // prints a\b\c\d
string b = a.Replace(@"\\", @"\");  
System.Console.WriteLine(b);  // prints a\b\c\d

You don't even need string b = a.Replace(@"\\", @"\");

score 1 · Accepted Answer · answered Jul 29 '13 at 07:46

In C#, you can't have a string like "a\b\c\d", because the \ has a special meaning: it creates a escape sequence together with a following letter (or combination of digits).

\b represents actually a backspace, and \c and \d are invalid escape sequences (the compiler will complain about an "Unrecognized escape sequence").

So how do you create a string with a simple \? You have to use a backslash to espace the backslash:\\ (it's the espace sequence that represents a single backslash).

That means that the string "a\\b\\c\\d" actually represents a\b\c\d (it doesn't represent a\\b\\c\\d, so no double backslashes). You'll see it yourself if you try to print this string.

C# also has a feature called verbatim string literals (strings that start with @), which allows you to write @"a\b\c\d" instead of "a\\b\\c\\d".

score 0 · Answer 4 · answered Mar 02 '15 at 04:43

0

this works

You don't even need string b = a.Replace(@"\", @"\");

but like if we generate a dos command through c# code... eg:- to delete a file this wil help

answered Mar 02 '15 at 04:43

score 0 · Answer 5 · edited Mar 30 '21 at 09:49

0

I did this in a code in a UWP application.

foreach (var item in Attendances)
{
   string a = item.ImagePath;
   string b = a.Replace(@"\\", "/");
   string c = a.Replace("\\", "/");

   Console.WriteLine(b);
   Console.WriteLine(a);
   item.ImagePath = c;
}

and the ones without the @ symbol is the one that actually worked. this is C# 8 and C# 9

edited Mar 30 '21 at 09:49

tmsbrndz

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answered Mar 30 '21 at 06:33

Rikudou En Sof

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Replace \\ with \ in C#

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