多个一维数组转换成一个一维数组

int[] arr1 = new int[] { 1, 2, 3 };
            int[] arr2 = new int[] { 4, 5, 6 };
            int n=arr1.Length+arr2.Length;
            int[] arr3=new int[n];
            for (int i = 0; i < n; i++)
            {
                if (i < arr1.Length)
                {
                    arr3[i] = arr1[i];
                }
                else
                {
                    arr3[i] = arr2[i - arr1.Length];
                }
            }
            foreach (int i in arr3)
            {
                Console.Write(i);
            }
            Console.Read();