Class Array referencing

Questions & Answers
1

I keep getting this “IndexOutOfRangeException: Array index is out of range.
grassPlain.createHandlerEntry () (at Assets/Scripts/Tiles/Grass/grassPlain.cs:32)
grassPlain.Start () (at Assets/Scripts/Tiles/Grass/grassPlain.cs:21)”

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class grassHandler : MonoBehaviour {

	public class glassPlain {
		public bool isOwned;
		public bool isBuilt;
		public bool isPlagued;

		public int population;
	}

	public grassPlain[] plain;

	// Use this for initialization
	void Start () {
		
	}
	
	// Update is called once per frame
	void Update () {
		
	}
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class grassPlain : MonoBehaviour {

	// Handler Information
	public bool hasEntry;
	public int tileNumber;

	public bool isOwned;
	public bool isBuilt;
	public bool isPlagued;
	public int population;

	// Script Information
	public grassHandler grassHandler;

	// Use this for initialization
	void Start () {
		createHandlerEntry ();
	}
	
	// Update is called once per frame
	void Update () {
		
	}

	void createHandlerEntry () {
		tileNumber = grassHandler.plain.Length + 1;
		grassHandler.plain = new grassPlain[tileNumber];
		grassHandler.plain [tileNumber].isOwned = false;
		grassHandler.plain [tileNumber].isBuilt = false;
		grassHandler.plain [tileNumber].isPlagued = false;
		grassHandler.plain [tileNumber].population = Random.Range (0, 100);
		Debug.Log (grassHandler.plain [tileNumber]);
	}
}



Any help would be appreciated, I've tried several different ways but I always end up with the same result, arrays and raycasting have been my struggles of late.
2

grassHandler.plain = new grassPlain[tileNumber]; Is not going to initialize the objects in the array. You will get a NullreferenceException on the next line, even without the IndexOutOfRangeException. The IndexOutOfRangeException would be solved by using grassHandler.plain [tileNumber - 1].isOwned = false;