Question

How to use StringBuilder in this code.

        string strFunc = "data /*dsdsds */ data1 /*sads dsds*/";
        while (strFunc.Contains("/*"))
        {
            int tempStart = strFunc.IndexOf("/*");
            int tempEnd = strFunc.IndexOf("*/", tempStart);

            if (tempEnd == -1)
            {
                tempEnd = strFunc.Length;
            }
            strFunc = strFunc.Remove(tempStart, tempEnd + 1 - tempStart);
        }

Logic is to remove commanded data from string

Answer 1

What you want to do is something like

string strFunc = "data /*dsdsds */ data1 /*sads dsds*/";
Regex reg = new Regex(@"/\*.+?\*/"); 
strFunc = reg.Replace(strFunc, String.Empty);

no StringBuilder is required here.

However, to provide an example to the use of a StringBuilder: to create a string which holds the removed ‘commands’, you could write

MatchCollection commands = reg.Matches(strFunc);
StringBuilder sb = new StringBuilder();
foreach (Match m in commands)
    sb.Append(m.ToString());

but you will have to beware of formatting here.

I hope this helps.