Use the Length array property
// Use the Length array property. using System; public class LengthDemo { public static void Main() { int[] nums = new int[10]; Console.WriteLine("Length of nums is " + nums.Length); for(int i=0; i < nums.Length; i++) nums[i] = i * i; Console.Write("Here is nums: "); for(int i=0; i < nums.Length; i++) Console.Write(nums[i] + " "); Console.WriteLine(); } }