int[] arr = new int[9]; //initialize the array, now it's [null,null,null,...];
for (int i = 0; i < arr.Length; i++)
{
Random rnd = new Random();
arr[i] =rnd.Next(0, 1001);
}
for (int i = 0; i < arr.Length; i++) // print a random arr, ^
{
Console.Write(", "+ arr[i]);
}