C# : algorithm "List" sample code

namespace List
{
    class Program
    {
        static void Main(string[] args)
        {
            List<int> list = new List<int>(new int[] { 19, 23, 29 });

            int index = list.IndexOf(23); // Check if 23 Exists.
            Console.WriteLine(index);

            index = list.IndexOf(10); // Does not exist.
            Console.WriteLine(index);

            list.Add(35);
            list.Insert(1, 40);
            list.Remove(23); // RemoveAt(index) method, or the Remove(obj)
            list.RemoveAt(0); // RemoveAt(index) method, or the Remove(obj)

            foreach (int x in list)
            {
                Console.WriteLine(x);    
            }

            Console.ReadLine();
        }
    }
}