Adding Items to a string array

Question

I need a way to prepend items on to an existing string array, such that:

string[] dirParams = null;
if (Request.Params["locationDirection_0"] != "")
{
 dirParams = Request.Params["locationDirection_0"].Split(',');
}
if (Request.Params["locationDirection_1"] != "")
{
 dirParams = Request.Params["locationDirection_1"].Split(',');
}
if (Request.Params["locationDirection_2"] != "")
{
 dirParams = Request.Params["locationDirection_2"].Split(',');
}
if (Request.Params["locationDirection_3"] != "")
{
 dirParams = Request.Params["locationDirection_3"].Split(',');
}

will give me a string array of about 4 items (assuming none of the requests coming in are empty)

whats the easiest way to do this, I thought of using a list and or a dictonary, neither will work for what I want to do, string array is all I want.

• Eugen Rieck: Why not use a List, then convert to array?
• Matthew Watson: Do you mean prepend? Or do you really mean append?

Answer 1

Use a list instead:

 List<string> dirParams = new List<string>();
 if (Request.Params["locationDirection_0"] != "")
 {
 dirParams.AddRange(Request.Params["locationDirection_0"].Split(','));
 }
 if (Request.Params["locationDirection_1"] != "")
 {
 dirParams.AddRange(Request.Params["locationDirection_1"].Split(','));
 }
 if (Request.Params["locationDirection_2"] != "")
 {
 dirParams.AddRange(Request.Params["locationDirection_2"].Split(','));
 }
 if (Request.Params["locationDirection_3"] != "")
 {
 dirParams.AddRange(Request.Params["locationDirection_3"].Split(','));
 }

Answer 2

Use a List<string> and then the ToArray() method to convert it into a string[].

Answer 3

Build your items in a List<string> then use LINQ's .ToArray () to convert it into an array.

• VisualMelon: Note that List.ToArray() isn't a component of LINQ.

Answer 4

How about using Linq?

var dirParam = Enumerable.Range(0, 4)
 .Select(i => Request.Params["locationDirection_" + i])
 .Where(s => !String.IsNullOrEmpty(s))
 .SelectMany(s => s.Split(','))
 .ToArray();