using System;

​

int[] list = {1, 2, 3, 4, 5, 6};

Func<int[], string> checkArray = array =>

{

    return array switch

    {

        // array.Length == 0

        [] => "Empty",

        // array.Length >=3 && array[0] == 1 && array[array.Length]-1] == 6 ... and also a few lines to get the middle values :P

        [1, ..var middle, 6] => $"The first element is 1, the middle is {middle}, the last one is 6",

        [1, .., > 2] => "The first element is 1 and the last one is bigger than 2",

​

        _ => "Other"

    };

};

Console.WriteLine(checkArray(list));