using System;using System.Collections;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace Array{  class Program  {    static void Main(string[] args)    {      int[] array = new int[] { 1, 2, 3 };      int[] des = addArray(array, 4, 4);       foreach (int item in des)      {        Console.WriteLine(item );      }      Console.ReadLine();    }    static int[] addArray(int[] bornArray, int index, int value)    {      ArrayList list = new ArrayList(bornArray );      if (index <0)      {        index =0 ;      }      if (index >bornArray .Length -1)      {        index = bornArray.Length;      }      list.Insert(index ,value );      int[] des = new int[list.Count ];      for (int i=0;i<list.Count;i++)      {        des[i] = (int)list[i];      }      return des;    }  }}