Question

I’m having two lists.

List A      List B
  a          10
  b           5
  c          20

I have to sort the List B ascending. Based on List B, List A also should reorder. So my result will be like this

List A      List B
 c          20
 a          10
 b          5

I’m using Linq here (orderby). Facing problem in sorting the other list. How can i do this?

Answer 1

One way would be

List<string> listA = new List<string> { "a", "b", "c" };
List<int> listB = new List<int> { 10, 5, 20 };

var joined = listA.Select((value, index) => Tuple.Create(value, listB[index]));

List<string> orderedListA = joined.OrderByDescending(t => t.Item2)
                                  .Select(t => t.Item1)
                                  .ToList();

Edit: I’ve missed the Zip method. The line

 var joined = listA.Select((value, index) => Tuple.Create(value, listB[index]));

could be written as

 var joined = listA.Zip(listB, (s,i) => Tuple.Create(s,i));