C# String.Replace double quotes and Literals

Question

I'm fairly new to c# so that's why I'm asking this here.

I am consuming a web service that returns a long string of XML values. Because this is a string all the attributes have escaped double quotes

string xmlSample = "<root><item att1=\"value\" att2=\"value2\" /></root>"

Here is my problem. I want to do a simple string.replace. If I was working in PHP I'd just run strip_slashes().

However, I'm in C# and I can't for the life of me figure it out. I can't write out my expression to replace the double quotes (") because it terminates the string. If I escape it then it has incorrect results. What am I doing wrong?

    string search = "\\\"";
    string replace = "\"";
    Regex rgx = new Regex(search);
    string strip = rgx.Replace(xmlSample, replace);

    //Actual Result  <root><item att1=value att2=value2 /></root>
    //Desired Result <root><item att1="value" att2="value2" /></root>

MizardX: To include a quote in a raw string you need to double it.

That's important information, trying that approach now...No luck there either There is something going on here with the double quotes. The concepts you all are suggesting are solid, BUT the issue here is dealing with the double quotes and it looks like I'll need to do some additional research to solve this problem. If anyone comes up with something please post an answer.

string newC = xmlSample.Replace("\\\"", "\"");
//Result <root><item att=\"value\" att2=\"value2\" /></root> 

string newC = xmlSample.Replace("\"", "'");
//Result newC   "<root><item att='value' att2='value2' /></root>"

Answer 1

Both the string and the regex uses \ for escaping. The regex will see the character \ followed by ", and think it's a literal escape. Try this:

Regex rgx = new Regex("\\\\\"");
string strip = rgx.Replace(xmlSample, "\"");

You could also use raw strings (also known as veratim strings) in C#. They are prefixed with @, and all back-slashes are treated as normal characters. To include a quote in a raw string you need to double it.

Regex rgx = new Regex(@"\""")
string strip = rgx.Replace(xmlSample, @"""");

Answer 2

There's no reason to use a Regular expression at all... that's a lot heavier than what you need.

string xmlSample = "blah blah blah";

xmlSample = xmlSample.Replace("\\\", "\"");

Answer 3

discorax are you looking at your output in the debugger?

if so print it out. The debugger escapes the quote's.

or look at it in the text visualizer.

Answer 4

If you are getting an XML string why not use XML instead strings?

you will have access to all elements and attributes and it will be much easier and extremely fast if using the System.Xml namespace

in your example you are getting this string:

string xmlSample = "<root><item att1=\"value\" att2=\"value2\" /></root>";

All you need to do is convert that string into a XML Document and use it, like:

System.Xml.XmlDocument xml = new System.Xml.XmlDocument();
xml.LoadXml(xmlSample);

System.Xml.XmlElement _root = xml.DocumentElement;

foreach (System.Xml.XmlNode _node in _root)
{
    Literal1.Text = "<hr/>" + _node.Name + "<br/>";
    for (int iAtt = 0; iAtt < _node.Attributes.Count; iAtt++)
        Literal1.Text += _node.Attributes[iAtt].Name + " = " + _node.Attributes[iAtt].Value + "<br/>";
}

in ASP.NET this will output to the Literal1 something like:

item
att1 = value
att2 = value2

once you have the element in a XmlElement, it is very easy to search and get the values and names for what's in that element.

give it a try, I use it a lot when retrieving WebServices responses and when I store something in a XML file as settings for a small application for example.

Answer 5

the following statement in C#

string xmlSample = "<root><item att1=\"value\" att2=\"value2\" /></root>"

will actually store the value

<root><item att1="value" att2="value2" /></root>

whereas

string xmlSample = @"<root><item att1=\""value\"" att2=\""value2\"" /></root>";

have the value of

<root><item att1=\"value\" att2=\"value2\" /></root>

for the second case, you need to replace the slash () by empty string as follow

string test = xmlSample.Replace(@"\", string.Empty);

the result will be

<root><item att1="value" att2="value2" /></root>

P.S.

1. slash (\) is default escape character in C#
2. to ignore slashes, use @ at the beginning of string
3. if @ is used, the escape character is double quote (")