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.
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".