Linq

ublic static class Expansion
    {
        public static double Sum(this List<int> tmp)
        {
            double S = 0;
            foreach (int i in tmp)
                S += i;
            return S;
        }
    }

    public class Good
    {
        public string Title { get; set; }
        public double Weight { get; set; }
        public decimal Price { get; set; }
        public DateTime DateOfArrival { get; set; }
        public int StorageNumber { get; set; }

        //public Good(string _Title, double _Weight, decimal _Price, DateTime _DateOfArrival, int _StorageNumber)
        //{
        //    Title = _Title;
        //    Weight = _Weight;
        //    Price = _Price;
        //    DateOfArrival = _DateOfArrival;
        //    StorageNumber = _StorageNumber;
        //}

        public void Print()
        {
            Console.WriteLine("{0} - {1} - {2} - {3} - {4}", Title, Weight, Price, DateOfArrival, StorageNumber);
            Console.WriteLine();
        }

    }

    public static class Program
    {
        static void Main(string[] args)
        {
            List<int> arr1 = new List<int>(){ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
            Console.WriteLine("Sum: {0}", arr1.Sum());
            List<Good> goodslist = new List<Good>()
            {
                new Good() { Title = "corn", Weight = 27.1 , Price = 21.5m, DateOfArrival = DateTime.Now.AddDays(1), StorageNumber = 1 },
                new Good() { Title = "ice", Weight = 30, Price = 13m, DateOfArrival = DateTime.Now.AddDays(2), StorageNumber = 1 },
                new Good() { Title = "car", Weight = 1, Price = 5.99m, DateOfArrival = DateTime.Now.AddDays(-3), StorageNumber = 2 },
                new Good() { Title = "toy", Weight = 15.7, Price = 3.75m, DateOfArrival = DateTime.Now.AddDays(6), StorageNumber = 3 },
                new Good() { Title = "biscuit", Weight = 12, Price = 43.6m, DateOfArrival = DateTime.Now.AddDays(8), StorageNumber = 2 }
            };

            var emp = from goods in goodslist
                      where goods.Price > 4
                      orderby goods.Price descending
                      select new
                      {
                          goods.Title,
                          goods.Price
                      };

            foreach (var item in emp)
            {
                Console.WriteLine("{0} - {1}", item.Title, item.Price);
            }

            var emp = from goods in goodslist
                      where goods.DateOfArrival > DateTime.Now(-1)
                      orderby goods.Price descending
                      select new
                      {
                          goods.Title,
                          goods.Price
                      };
            oderby

            foreach (var item in emp)
            {
                Console.WriteLine("{0} - {1}", item.Title, item.Price);
            }



            var group = from good in goodslist
                        group good by good.StorageNumber;

            foreach (var item in group)
            {
                Console.WriteLine(item.Key);
                foreach (var gr in item)
                {
                    gr.Print();
                }
                Console.WriteLine();
            }