c# how to append arrays without duplicates

Question

The below example splits two strings of codes and appends them together. The problem is it doesn't filter duplicates. In this case allCodes has "DL" twice. Is there a way to do the split & concatenate without dups?

        string carCodes = "DL, UL, AL, ";
        string airCodes = "RL, DL";

        string[] allCodes = airCodes
          .Replace(" ", "")
          .Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries)
          .Concat(carCodes
             .Replace(" ", "")
             .Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries))
          .ToArray();

Answer 1

A distinct does it.

.Distinct().ToArray();