String.join array from last element

Question

I have a scenario where I am getting a comma separated string LastName, FirstName. I have to convert it into FirstName LastName.

My code is below:

Public static void main(string [] args)
{
      var str = "Lastname, FirstName":
      var strArr = str.Split(',');
      Array. Reverse(strArr);
      var output = string.join(" ", strArr);
}

Is there a better way to do this, like in one line or using LINQ?

Answer 1

Yes there is already a Reverse extension method for IEnumerables:

var output = string.Join(" ",str.Split(',').Reverse());

Answer 2

This takes care of a lot of the various edge cases. You mentioned one but did not include it in your initial question so I assume there could be others.

var tests = new[]{"Lastname, FirstName", "Lastname, ", ", FirstName", "Lastname", "FirstName"};
foreach(var str in tests)
{
    var strArr = str.Split(new[] {','}, StringSplitOptions.RemoveEmptyEntries)
        .Where(x => !string.IsNullOrWhiteSpace(x))
        .Reverse()
        .Select(x => x.Trim());
    var output = string.Join(" ", strArr);
    Console.WriteLine(output);
}

Working Fiddle

Answer 3

Use Aggregate and Trim your names after splitting, you do not need reversing.

 str.Split(',').Aggregate((lname, fname) => fname.Trim() + " " + lname.Trim())

Answer 4

Below is my new code:

Public static void main(string [] args)
    {
          var str = "Lastname, FirstName":
          var strArr = str.Split(',').Select(p=>p.Trim()).ToArray();
          var output = string.join(" ", strArr.Reverse());
    }