Question

Why am I getting this error?

public class ParameterParser
{
    public List<string> ParseParameter(string queryString)
    {
        queryString = queryString.Replace(" ", "");

        string[] strs = queryString.Split(@"(", @"=", @",", @"<>", 
                                          StringSplitOptions.None);

        List<string> parameters = new List<string>();

        foreach (string ss in strs)
        {
            string s = ss.Trim(')');

            if (s.StartsWith("@") && !s.Equals("") && s!=null)
            {
                parameters.Add(s.Replace(" ", ""));
            }
        }

        return parameters;
    }
}

Error 3 The best overloaded method match for ‘string.Split(params char[])’ has some invalid arguments F:…\ParameterParser.cs

Answer 1

If you want to pass an array of strings, you have to do that explicitly:

string[] strs = queryString.Split(new string[] {"(", "=", ",", "<>"}, 
                                  StringSplitOptions.None);

I suspect you were modelling your code on something like this:

string[] strs = queryString.Split('(', '=', ',');

This is using a parameter array (the params modifier in C#). Parameter arrays are only applicable for the final parameter, and no overload of String.Split takes a params string[]. That’s why it wasn’t working for you.

Note that I’ve changed the strings into simple string literals – I would recommend only using verbatim string literals when you actually need to.