Problems adding to a Builtin Array in C#

I'm managing to grab the data I need out of an XML file, and since I'm working in C# I'm having to set the length of the array by reinitialising it. The problem seems to be that the array isn't done initialising by the time I try to add some data to it (I'm getting a NullReferenceException).

I'm pretty sure of this just because if I try to change any part of the array in Update I'll get more NullReferenceExceptions and then it will eventually work. Any suggestions? Here's what I'm using:

 using UnityEngine;
 using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Xml;
 
 public class MyDataTesting : MonoBehaviour
 {
     public MyClass[] myClasses;
     
     private XmlDocument xmlDoc;
     private string url;
     private WWW www;
     private string xml;
     
     IEnumerator Start()
     {
         url = "myurl";
         www = new WWW(url);
         yield return www;
         xml = www.text;
         LoadDatabase();
     }
     
     void LoadDatabase()
     {
         xmlDoc = new XmlDocument();
         xmlDoc.LoadXml(xml);
         XmlNode root = xmlDoc.FirstChild;
         
         if(root.HasChildNodes)
         {
             myClasses = new MyClass[root.ChildNodes.Count];
             
             for(int i=0; i<root.ChildNodes.Count; i++)
             {
                 myClasses[i].name = root.ChildNodes[i].Attributes["name"].Value;
             }
         }
     }
 }
 
 [Serializable]
 public class MyClass
 {
     public string name;
     public int price;
 }