Arrays resized dynamically

In C#, arrays cannot be resized dynamically. One approach is to use System.Collections.ArrayList instead of a native array. Another (faster) solution is to re-allocate the array with a different size and to copy the contents of the old array to the new array. The generic function resizeArray (below) can be used to do that.
Example is bellow

public static System.Array ResizeArray (System.Array oldArray, int newSize) {      int oldSize = oldArray.Length;     System.Type elementType = oldArray.GetType().GetElementType();     System.Array newArray = System.Array.CreateInstance(elementType,newSize);     int preserveLength = System.Math.Min(oldSize,newSize);   if (preserveLength > 0)          System.Array.Copy (oldArray,newArray,preserveLength);   return newArray; }

How to Test ResizeArray().

public static void Main () {      int[] a = {1,2,3};     a = (int[])ResizeArray(a,5);     a[3] = 4;     a[4] = 5;     for (int i=0; i <a.Length;a++)    {          System.Console.WriteLine ("Aarray of  "+i+" is "+a[i]);     } }

Out Put is:

Aarray of  0 is1 Aarray of 1 is 2 Aarray of 2 is 3 Aarray of 3 is 4 Aarray of 4 is5