/*

                LINQ has a bunch of KEY types

                two most notable ones are the SELECT and WHERE.

             */

            // WHERE conditions

            List<int> myList = new List<int>();

            myList.AddRange(Enumerable.Range(1,100));
            List<int> myList2 = new List<int>();

            myList2.AddRange(Enumerable.Range(1, 50));
            var divisby2 = myList.Where(
                    a => a % 2 == 0
                ).ToList();


            foreach (object x in divisby2)
                Console.WriteLine($"val divis by 2 : {x}");


            // SELECT execute function on each element


            var divisby5 = from x in myList
                           where x % 5 == 0 select x;


            foreach (object x in divisby5)
                Console.WriteLine($"val divis by 5 : {x}");

            var match = from x in myList
                        join y in myList2 on x equals y

                        select x;


            foreach (object x in match)
                Console.WriteLine($"val is the same: {x}");


            //distinct

            List<int> notdistinct = new List<int>()
            {
                1,2,3,3,3,3,6,7,8,9,10
            };

            Console.WriteLine("------------------");

            foreach (object x in notdistinct)
                Console.WriteLine($"Elements of not distinct: {x}");


            var nowdistinct = notdistinct.Distinct();

            foreach (object x in nowdistinct)
                Console.WriteLine($"Elements of distinct: {x}");

            Console.WriteLine("------------------");


            var sqlDistinct = from x in notdistinct.Distinct()
                              select x;