Finding Coordinates of Objects in a List

I made a list of Tiles that are instantiated. I want to retrieve a location of objects later in a new function. I tried using transform.position and GetComponent().transform.position but I keep getting NullReferenceException: Object reference not set to an instance of an object. This line is where the error occurs:
Debug.Log ("Tiles: " + tiles*.GetComponent().transform.position);*

  • public List tiles = new List();*

  • public int gridWidth;*

  • public int gridHeight;*

  • public GameObject tilePrefab;*

  • // Use this for initialization*

  • void Start () {*

  •   for (int y = 0; y < gridHeight; y++) {*
    
  •   	for (int x = 0; x < gridWidth; x++)*
    
  •   	{*
    
  •   		GameObject g = Instantiate(tilePrefab, new Vector3(x,y,1), Quaternion.identity) as GameObject;*
    
  •   		g.transform.parent = gameObject.transform;*
    
  •   		tiles.Add(g.GetComponent<Tile>());*
    
  •   	}*
    
  •   }*
    
  •   gameObject.transform.position = new Vector3 (-3.5f, -3.5f, 1);*
    
  • }*

  • public void CheckTiles(){*

  •   	for (int i = 0; i < tiles.Count; i++) {	*
    
  •   		Debug.Log ("Tiles Count: " +tiles.Count);*
    

_ Debug.Log ("Tiles: " + tiles*.GetComponent().transform.position);_
_ Debug.Log("tiles : " + tiles.transform.position);
}
}*_