Add Item in Array

public static int[] AddNewItem(int[] c, int newV)

        {

                //int[] a = new int[c.Length + 1];

                //for (int i = 0; i < c.Length; i++)

                //{

                //    a[i] = c[i];

                //}

                //a[c.Length] = newV;

                c.ToList<int>().Add(newV);

                c.ToArray();

                return c;

        }

static void Main(string[] args)

        {

int[] arr1 = new int[] { 3, 4, 5 };

            int[] arr4 = new int[3] { 3, 4, 5 };

            int[] arr3 = AddNewItem(arr1, 10);

}