using System;

using System.Collections.Generic;

​

namespace FuncoesPuraseSideEffects

{

    class Program

    {

        public static List<int> ReturnIntListXs2(List<int> list)

        {

            for (int i = 0; i < list.Count; i++)

            {

                list[i] = list[i] * 2;

            }

            return list;

        }

        static void Main(string[] args)

        {

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

            for (int i = 0; i < 10; i++)

            {

                list.Add(i);

            }

            List<int> res = ReturnIntListXs2(list);

            foreach (int s in res)

            {

                Console.Out.WriteLine(s);

            }

            Console.In.ReadLine();

        }

    }

}

​