Using / or \\ for folder paths in C#

Question

When writing file paths in C#, I found that I can either write something like "C:\" or "C:/" and get the same path. Which one is recommended? I heard somewhere that using a single / was more recommended than using \ (with \ as an escaped sequence).

Hyperostosis

Thanks to John Saunders for pointing out this is a Windows issue. I heard using / is better for cross-compatibility, which doesn't matter too much here as I'm targeting Windows. – Hyperostosis

Bug in title: should be "/ or \\", not "// or \". – Lobbyist

@sblom- Not sure the exact difference, but fixed since it works :p – Hyperostosis

Answer 1

Windows supports both path separators, so both will work, at least for local paths (/ won't work for network paths). The thing is that there is no actual benefit of using the working but non standard path separator (/) on Windows, especially because you can use the verbatim string literal:

string path = @"C:\"  //Look ma, no escape

The only case where I could see a benefit of using the / separator is when you'll work with relative paths only and will use the code in Windows and Linux. Then you can have "../foo/bar/baz" point to the same directory. But even in this case is better to leave the System.IO namespace (Path.DirectorySeparatorChar, Path.Combine) to take care of such issues.

Garland

What you're calling "raw string operator" is really "verbatim string literal". – Dunnage

@Jay: "Verbatim string literal operator"? or just "Verbatim string literal"? – Garland

Even if you're writing code to use on posix and Windows, you should still use the right one. There are many (third-party) abstractions to make this easy, one such being path_util in Chromium. – Eurhythmic

@jeffamaphone: I agree. That's what I say in the final phrase, but in this case there's no need for third party abstractions. – Garland

There's a problem with the last paragraph where some sort of files like config files that contain text with directory paths could be generated on different OSes and then shared between them. Windows will want to use backslashes while Mac will expect forward slashes. – Protolanguage

Times have changed, and .NET apps now run on Linux. I'd use Path.Combine() so that the runtime automatically selects the correct path separator. – Backcourt

Answer 2

Please use Path.DirectorySeparatorChar OR better, as Poita suggested use Path.Combine.

Ragged

Path.PathSeparator is a character to split paths in the PATH environment variable. On Windows it is ;. I updated this answer to refer to DirectorySeparatorChar. – Inanimate

Oops. Thank you for the correction, I did mean to post about DirectorySeparatorChar. – Ragged

Answer 3

I write paths in C# like this:

var path = @"C:\My\Path"

The @ character turns off \ escaping.

EDIT a decade later

.NET now runs on Linux. Use Path.Combine() where feasible, otherwise use Path.DirectorySeparatorChar to construct a path with \ or / as appropriate to the underlying OS.

Backcourt

Answer 4

Use Path.Combine and you don't need to worry about such semantics.

Enculturation

It's too bad that Path.Combine takes only 2 parameters. – Metaphysical

@MikeCole since .NET 4.0, an overload takes any number of parameters via params keyword. – Cockalorum

Answer 5

This isn't a C# issue - it's a Windows issue. Paths in Windows are normally shown with a backslash: C:\. In my opinion, that's what you should use in C#. Use @"C:\" to prevent special handling of backslash characters.

Walkout

Answer 6

.Net Framework 4.8 (VS 2022)

If I am using this:

string myPath = @"C:\myFile.txt";

It's throw an exception "Access to the path 'C:\myFile.txt' is denied.'"

But When I am creating a folder in C:\ then it is working.

 string myPath = @"C:\mie\myFile.txt";

Heavenly