convert a string[] to string with out using foreach

Question

string x;
foreach(var item in collection)
{
   x += item+",";
}

can I write something like this with lambdas?

Answer 1

Assuming C#, have you tried String.Join()? Or is using lambdas mandatory?

Example:

string[] myStrings = ....;
string result = String.Join(",", myStrings);

EDIT

Although the original title (and example) was about concatenating strings with a separator (to which String.Join() does the best job in my opinion), the original poster seems to ask about the broader solution: how to apply a custom format a list of strings.

My answer to that is write your own method. String.Join has a purpose, reflected by its name (joins some strings). It's high chance that your format logic has a meaning in your project, so write it, give it a proper name and use it.

For instance, if you want to output <li>text</li> for every item, make something as this:

string FormatAsListItems(string[] myStrings)
{
    StringBuilder sb = new StringBuilder();
    foreach (string myString in myStrings)
    {
         sb.Append("<li>").Append(myString).Append("</li>");
    }
}

I think the intent is clearer, and you also don't take the performance hit of concatenating strings in a loop.

Answer 2

string x = string.Join(",", collection);

Answer 3

You are looking too far for the solution. The String class has a Join method for this:

string x = String.Join(",", collection);

Answer 4

Does this answer your question?

Most efficient way to concatenate strings?

Note that you can do this with Aggregate, but the built-in string.Join is both easier to use and faster for long arrays.

Answer 5

string[] text = new string[] { "asd", "123", "zxc", "456" };

var result = texts.Aggregate((total, str) => total + "," + str);

Shorter syntax, thanks to Earwicker