Question

How can I convert my list of strings:

List<string> appliedFilters = filterString.Split(',').Select(n => n).ToList();

Into a list without duplicates?

My list of strings (appliedFilters) looks like this:

7-27,
2-37,
7-28,
9-18,
9-22,
9-80

I need to output this list without duplicates in the first part of the string, e.g:

7-27-28, 2-37, 9-18-22-80

I’m sure there’s a LINQ query here somewhere, but cannot figure it out.

Answer 1

filterString.Split(',')
  .Select(s => s.Split('-'))
  .GroupBy(ss => ss[0])
  .Select(group => string.Join("-", new[]{group.Key}.Concat(group.Select(ss => ss[1])).ToArray()));