// Type: long?, selector function is called public static int Test4g() { Data_Nlong[] source = new Data_Nlong[]{ new Data_Nlong{name="Tim", num=null}, new Data_Nlong{name="John", num=Int64.MinValue}, new Data_Nlong{name="Bob", num=-10L} }; long? expected = Int64.MinValue; var actual = source.Min((e) => e.num); return ((expected == actual) ? 0 : 1); }