Linq 之Concat/Union/Intersect/Except/Distinct

　　　　List<int> list1 = new List<int> { 1,2,3,4};
           List<int> list2 = new List<int> { 3,4,5,6};

           var r = list1.Except(list2).ToList(); //result: 1,2

           r = list2.Except(list1).ToList();     //result: 5,6

           r = list1.Intersect(list2).ToList();  //result: 3,4

           r = list1.Union(list2).ToList();      //result: 1,2,3,4,5,6

           r = list1.Concat(list2).ToList();     //result: 1,2,3,4,3,4,5,6

           r = r.Distinct().ToList();            //result: 1,2,3,4,5,6