Adding List.add() another list

Question

I have an IEnumerable and I am trying to add the vales in the for-loop to a List. I keep get

Answer 1

List.Add adds a single element. Instead, use List.AddRange to add multiple values.

Additionally, List.AddRange takes an IEnumerable, so you don't need to convert tripDetails into a List, you can pass it directly, e.g.:

tripDetailsCollection.AddRange(tripDetails);