Resizable Array

            int?[] myArr = new int?[4];

            string command = string.Empty;
            int cnt = 0;

            while (!command.Equals("end"))
            {
                command = Console.ReadLine();

                if (command.Contains("push"))
                {
                    int number = int.Parse(command.Split().Last());

                    myArr[cnt] = number;
                    cnt++;

                    if (cnt == myArr.Length)
                    {
                        Array.Resize<int?>(ref myArr, myArr.Length * 2);
                    }
                }

                else if (command.Contains("removeAt"))
                {
                    int index = int.Parse(command.Split().Last());

                    myArr[index] = null;

                    for (int i = index; i < myArr.Length - 1; i++)
                    {
                        myArr[i] = myArr[i + 1];
                    }

                    cnt--;
                }

                else if (command.Equals("pop"))
                {
                    myArr[cnt - 1] = null;

                    cnt--;
                }

                else if (command.Equals("clear"))
                {
                    for (int i = 0; i < myArr.Length; i++)
                    {
                        myArr[i] = null;

                        Array.Resize<int?>(ref myArr, 4);
                    }

                    cnt = 0;
                }
            }

            if (myArr[0] == null)
            {
                Console.WriteLine("empty array");
            }
            else
            {
                Console.WriteLine(string.Join(" ", myArr));
            }