In f# for example you can write: let result = list1 |> List.filter (fun e -> ...) |> List.map (fun e -> ...) |> .... no

In f# for example you can write: let result = list1 |> List.filter (fun e -> ...) |> List.map (fun e -> ...) |> .... no mutation, but you are piping the intermediate result to the next operation. In c# you could achieve a similar result by using the dot operator instead of the backpiping |> one.