LINQ C#

Find the Second Max in a list of values using linq c#

List<double> ListOfNums = new List<double> {1, 5, 7, -1, 4, 8};

var secondMax = ListOfNums.OrderByDescending(r => r).Skip(1).FirstOrDefault();

OR

var secondMax = ListOfNums.OrderByDescending(r=> r).Take(2).LastOrDefault();

Left Join in linq in C#

from lst1 in TXs
       join lst2 in TYs on lst1.ID equals lst2.ID into yG
       from y1 in yG.DefaultIfEmpty()
       select new { X = lst1, Y =y1 }