C# อยากถามเรื่องวน for และเก็บข้อมูลลงตัวแปร array ค่ะ

  string[] arr = { "ManUTD", "Liverpool", "Arsenal", "Chelsea", "Chonburi FC", "Sisaket FC" };
        for (int i = 0; i < arr.Length; i++)
        {
            Response.Write("ตำแหน่งที่ " + (i) + " = " + arr[i] + "<br>");
        }

        string[] arr;
        int n = 10;
        arr = new string[n];
        for (int i = 1; i <= n; i++)
        {
            arr[i] = i.ToString();
        }

int[] a = { 1, 5, 10, 15, 20 };

foreach (int b in a)
{
    Response.Write(b + "<br />");
}

        int n = 10;
        int Sum = 0;
        int[] Point = new int[n];

        for (int i = 0; i < n; i++)
        {
            Point[i] = 1 + i;
            Sum += Point[i];
        }
        for (int i = 0; i < n; i++)
        {
            Response.Write("Point[" + i + "] = " + Point[i] + "<br />");
        }
        Response.Write("Summary = " + Sum + "");