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.
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(#"\\", #"\");
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".
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(#"\\", #"\");
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
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
Related
var a = "asdfgh\r";
Console.WriteLine(a.Contains(#"\r"));
var b = a.Replace(#"\r","").Replace(#"\n","");
var c = a.Replace("\r","").Replace("\n","");
Console.WriteLine(a);
Console.WriteLine(b);
Console.WriteLine(c);
"b" and "c" prints same string and "a" prints false,
I was trying to replace \r and \n to an empty char so first i tried below code, there's a backslash in "\r" and "\n" so i decided to use "#" before them ;
var b = a.Replace(#"\r","").Replace(#"\n","")
but this didn't work,
var c = a.Replace("\r","").Replace("\n","");
this works, so im confused when should i use "#" charachter ?
You declared string a to end with carriagereturn character:
var a = "asdfgh\r"; //it has a length of 7 when compiled
So you must replace the carriage return with nothing:
Replace("\r","")
If you had declared the string to end with "backslash r":
var a = #"asdfgh\r"; //it has a length of 8 when compiled
Then you would have succeeded in replacing "backslash r" with nothing:
Replace(#"\r","")
This would also work:
Replace("\\r","")
Because the double slash is turned into a single and then the r is a normal character so you're replacing "backslash r" and not carriagereturn
When compiling the C# compiler looks for \ in a string and converts the following character(s) according to some rule. Using # before the string turns this off. Mostly it's useful for paths. Remember that it's a compile time thing, not something you need to do to variables that hold data entered in runtime. Putting an # before a variable name means something different - allowing you to call a variable a reserved word, like string #for = "for" - deplorable practice; don't do it
Ultimately the problem is that you were inconsistent when declaring your strings - a was not a verbatim string so it really did have a single carriage return char, and then you were trying to replace using a verbatim string (and "backslash r" is a different string to "carriagereturn"
string s = "P\04";
string z = s.Replace('\\', '-');
Console.WriteLine(z);
I need to replace '\' character in to '-' character in a string. I tried several ways to replace, couldn't able to do for '\' character only.
Please any one suggest a way to do this
Your code to replace the \ is fine. The problem is with your input string, where the \ escapes the 0. It would work if you had this:
string s = "P\\04";
string z = s.Replace('\\', '-');
Console.WriteLine(z);
The output is P-04 assuming that's what you expect.
string s = #"P\04";
string z = s.Replace('\\', '-');
Console.WriteLine(z);
Add # at the before value of string s to make it a verbatim. That way '\' is treated as is. Otherwise \0 are treated as one character to make a different character.
You can also use Regex,
var result = Regex.Replace(#"P\04", #"\\", #"-");
Console.WriteLine(result);
FIDDLE
string testStr="thestringhasa\slash";
if(testStr.Contains("\"))
{
//Code to process string with \
}
How do I properly test to see if a string contains a backslash, when I try the it statement if says a New Line in constant.
The other two answers are entirely correct, but no one bothered to explain why. The \ character has a special purpose in C# strings. It is the escape character, so to have a string that contains a slash, you have to use one of two methods.
Use the string literal symbol #. A string preceded by the # symbol tells the C# compiler to treat the string as a literal and not escape anything.
Use the escape character to tell the C# compiler there is a special character that is actually part of the string.
So, the following strings are equivalent:
var temp1 = #"test\test";
var test2 = "test\\test";
test1 == test2; // Yields true
You should use double slashes
string testStr=#"thestringhasa\slash";
if(testStr.Contains("\\"))
{
//Code to process string with \
}
The backslash must be escaped. Try the following:
string testStr = #"thestringhasa\slash";
if (testStr.Contains("\\"))
{
//Code to process string with \
}
I have a string that contains sequence of three "\" and I have to replace them with single "\".
the string is:
string sample = "<ArrayOfMyObject xmlns:i=\\\"http://www.w3.org/2001/XMLSchema-instance\\\"";
I have tried, as suggested in other threads, with the following code but it did not work:
string result = sample.Replace(#"\\\",#"\");
string result = sample.Replace("\\\\\\","\\");
thanks in advance
In your sample, your string doesn't actually have three "\" characters in it - Some of them are escape characters.
\ will actually correspond to a single \ character.
\" will actually correspond to a single " character.
The value of your string, in memory, is:-
<ArrayOfMyObject xmlns:i=\"http://www.w3.org/2001/XMLSchema-instance\"
So, your replace operations do nothing because they do not match anything.
To replace \\\ with \ in a c# string try this code (tested and working)
string strRegex = #"(\\){3}";
string strTargetString = #"sett\\\abc";
var test=Regex.Replace(strTargetString, strRegex, #"\"); //test becomes sett\abc
in debug you will see test=sett\\abc (2 backslashes but one is an escape).
Don't worry and go to text Visualizer and you'll see the correct value
then
in your specific case the code will be
string sample = #"<ArrayOfMyObject xmlns:i=\\\"http://www.w3.org/2001/XMLSchema-instance\\\"";
var result=Regex.Replace(sample , strRegex, #"\");
the output of both of the replaces is
<ArrayOfMyObject xmlns:i=\"http://www.w3.org/2001/XMLSchema-instance\"
this looks correct
but maybe you have to add 6 instead of 3 '\' in your input, because there caracters are escape characters.
I have a string which contains backward slashes and I want to reply it with forward slashes
string filename = "te\test";
var x = filename.Split('\\');
Console.WriteLine(filename);
Console.ReadLine();
I have tried something like this but it is getting the same string "te\test" into x.
Is there any other way to do this?
You original string is not:
te\test
it's:
te{tab}est
\t is the tab character. So you can't split on the \ because you original string doesn't have a \
If you do something like this:
string filename = "te\\test";
var x = filename.Split('\\');
Console.WriteLine(string.Join("/",x));
You'll get the result you wanted.
But you really don't need to Split and Join when you can just Replace:
Console.WriteLine(filename.Replace('\\','/'));
Note: you can use # with your original string to make it a literal string (escapes are ignored) as #Joeb454 suggests (and that's usually what I'll do), but unfortunately the same trick doesn't apply to chars so you can't, for example, do #'\'.
Your initial string appears to be wrong, you're escaping the 't', giving you a tab character, it should be string filename = "te\\test";
You could also declare it as string filename = #"te\test"; - preceding the string with the # sign indicates to the compiler that it's a literal string, and therefore nothing will be escaped.
string filename = "te\test";
string[] x = filename.Split('\\');
Console.WriteLine(filename);//this line should be Console.WriteLine(x[0]+X[1]);
Console.ReadLine();
But I think you are looking for
filename = filename.Replace("\\","/");
Console.WriteLine(filename);