Add special characters to string value to display Fax Number using C#-CodePudding

I have string value like below example for fax

string fax="1111111111";

I need below result for above string to add special character for fax format like below.

(111)-111-1111

my code for reference because my question going down please help any to get result

        var list = (dynamic)null;
        if (!String.IsNullOrEmpty(faxdos.medicalRecordsFax) && !String.IsNullOrEmpty(faxdos.fax))
        {

            list = new List<SelectListItem>
        {
          new SelectListItem{ Text=String.Format("{0:(###)-###-####}", faxdos.medicalRecordsFax) " - Medical Records Fax", Value = faxdos.medicalRecordsFax},
          new SelectListItem{ Text=String.Format("{0:(###)-###-####}", faxdos.fax), Value = faxdos.fax },
        };
        }
        else if (!String.IsNullOrEmpty(faxdos.medicalRecordsFax))
        {
            list = new List<SelectListItem>
        {
          new SelectListItem{ Text=String.Format("{0:(###)-###-####}", faxdos.medicalRecordsFax) " - Medical Records Fax", Value = faxdos.medicalRecordsFax},

        };
        }
        else if (!String.IsNullOrEmpty(faxdos.fax))
        {
            list = new List<SelectListItem>
        {
          new SelectListItem{ Text=String.Format("{0:(###)-###-####}", faxdos.fax), Value = faxdos.fax },
        };
        }
        else
        {
            list = new List<SelectListItem>
        {
          new SelectListItem{ Text="", Value = "" },
        };
        }
        // ViewBag.emp = list;
        var result = new SelectList(list, "Text", "Value");
        

        return Json(result, JsonRequestBehavior.AllowGet);

CodePudding user response：

well how about just writing code to do it

string fax="1111111111";

string str2 = $"({fax.Substring(0,3)})-{fax.SubString(3,3)}-{fax.Substring(6,4)}";

CodePudding user response：

If you want to use the var result = string.Format("{0:(###)-###-####}", someValue) formatting mechanism, then the value you are formatting needs to be a number, not a string. So you could do something like this:

var telNoString = "1111111111";
if (long.TryParse(telNoString, out var telno))
{
    var result = string.Format("{0:(###)-###-####}", telno);
    Debug.WriteLine(result);
}

Which will result in (111)-111-1111 in the debug console.