Question

I have a string that is returned to me which contains escape characters.

Here is a sample string

“test\40gmail.com”

As you can see it contains escape characters. I need it to be converted to its real value which is

“[e-mail]”

How can I do this?

Answer 1

If you are looking to replace all escaped character codes, not only the code for @, you can use this snippet of code to do the conversion:

public static string UnescapeCodes(string src) {
    var rx = new Regex("\\\\([0-9A-Fa-f]+)");
    var res = new StringBuilder();
    var pos = 0;
    foreach (Match m in rx.Matches(src)) {
        res.Append(src.Substring(pos, m.Index - pos));
        pos = m.Index + m.Length;
        res.Append((char)Convert.ToInt32(m.Groups[1].ToString(), 16));
    }
    res.Append(src.Substring(pos));
    return res.ToString();
}

The code relies on a regular expression to find all sequences of hex digits, converting them to int, and casting the resultant value to a char.