Why does .NET add an additional slash to the alrea

Question

I've noticed that C# adds additional slashes (\) to paths. Consider the path C:\Test. When I inspect the string with this path in the text visualiser, the actual string is C:\\Test.

Why is this? It confuses me, as sometimes I may want to split the path up (using string.Split()), but have to wonder which string to use (one or two slashes).

Answer 1

Debugger visualizers display strings in the form in which they would appear in C# code. Since \ is used to escape characters in non-verbatum C# strings, \\ is the correct escaped form.

Answer 2

The \\ is used because the \ is an escape character and is need to represent the a single \.

So it is saying treat the first \ as an escape character and then the second \ is taken as the actual value. If not the next character after the first \ would be parsed as an escaped character.

Here is a list of available escape characters:

\' - single quote, needed for character literals
\" - double quote, needed for string literals
\\ - backslash
\0 – Null 
\a - Alert 
\b - Backspace 
\f - Form feed 
\n - New line 
\r - Carriage return 
\t - Horizontal tab 
\v - Vertical quote 
\u - Unicode escape sequence for character 
\U - Unicode escape sequence for surrogate pairs. 
\x - Unicode escape sequence similar to "\u" except with variable length.

EDIT: To answer your question regarding Split, it should be no issue. Use Split as you would normally. The \\ will be treated as only the one character of \.

Answer 3

Okay, so the answers above are not wholly correct. As such I am adding my findings for the next person who reads this post.

You cannot split a string using any of the chars in the table above if you are reading said string(s) from an external source.

i.e,

string[] splitStrings = File.ReadAllText([path]).Split((char)7);

will not split by those chars. However internally created strings work fine.

i.e.,

string[] splitStrings = "hello\agoodbye".Split((char)7);

This may not hold true for other methods of reading text from a file. I am unsure as I have not tested with other methods. With that in mind, it is probably best not to use those chars for delimiting strings!

Answer 4

.Net is not adding anything to your string here. What your seeing is an effect of how the debugger chooses to display strings. C# strings can be represented in 2 forms

• Verbatim Strings: Prefixed with an @ sign and removes the need o escape \\ characters
• Normal Strings: Standard C style strings where \\ characters need to escape themselves

The debugger will display a string literal as a normal string vs. a verbatim string. It's just an issue of display though, it doesn't affect it's underlying value.