Save Gameobject in Array

Hello everyone, For some reason, saving a gameobject in an array is not working for me. Granted, I have never worked with arrays before, but I can't find what I am doing incorrectly. My code is this:

 using UnityEngine;
 using System.Collections;
 
 public class createContact : MonoBehaviour {
 
     public GameObject newContact;
     public Vector3 NEWcontactSpawn;
     public int contactCount;
     int i = 0;
     public GameObject[] ContactArray;
 
     //declare variables
     void Start ()
     {
 
         ContactArray [4] = newContact;
 }

and I get an error stating that the array index is out of range. The gui array interface in unity says that the array is 0 items long. I am not sure what is wrong here. Thank you for the help. Sincerely, Wolfshadow