# Getting NullReferenceException when creating class instance using List

**URL:** https://discussions.unity.com/t/getting-nullreferenceexception-when-creating-class-instance-using-list/122526
**Category:** Questions & Answers
**Created:** [November 16, 2014, 10:41pm UTC](https://discussions.unity.com/t/getting-nullreferenceexception-when-creating-class-instance-using-list/122526 "2014-11-16T22:41:32Z")
**Posts on this page:** 2
**Page:** 1

<div class="post-metadata">

### Author: ![chetanisinanand](https://dub1.discourse-cdn.com/unity/user_avatar/discussions.unity.com/chetanisinanand/32/476145_2.png) [@chetanisinanand](https://discussions.unity.com/u/chetanisinanand)
#### Post date: [November 16, 2014, 10:41pm UTC](https://discussions.unity.com/t/getting-nullreferenceexception-when-creating-class-instance-using-list/122526/1 "2014-11-16T22:41:32Z")

</div>

I’m trying to create instance of class using List instead of array and getting error ,  
i don’t know the exact cause

please let me know if there is any workaround to use List of Class objects  
Thanks in advance for any suggestion or code !

```
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
    
[System.Serializable] public class BaseClass{
public int index ;
public List<GameObject> itemList;
}

public class GameLogicClass : MonoBehaviour {

public List<BaseClass> baseClassInstance;

	void Start(){

		for(int _m = 0;_m < 10;_m++){

					baseClassInstance.Add(new BaseClass());
					baseClassInstance[_m].index = 1;

		}

		Debug.Log(baseClassInstance[0].itemList.Count ); // < Getting ERROR here : NullReferenceException: Object reference not set to an instance of an object GameLogicClass.Start () 

	}
}

```

---

<div class="post-metadata">

### Author: ![Scribe](https://dub1.discourse-cdn.com/unity/user_avatar/discussions.unity.com/scribe/32/44261_2.png) [@Scribe](https://discussions.unity.com/u/Scribe)
#### Post date: [November 16, 2014, 10:55pm UTC](https://discussions.unity.com/t/getting-nullreferenceexception-when-creating-class-instance-using-list/122526/2 "2014-11-16T22:55:12Z")

</div>

I think you need to define what the list is of (though this may be optional as it sounds like you aren’t getting an error here)

```
public List<BaseClass> baseClassInstance;

```

and you need to initialise the list somwhere:

```
void Start(){
	baseClassInstance = new List<BaseClass>();
	for(int _m = 0;_m < 10;_m++){
		baseClassInstance.Add(new BaseClass());
		baseClassInstance[_m].index = 1;
	}
	Debug.Log(baseClassInstance[0].itemList.Count );
}

```

Also in future can you highlight all your code and hit the ‘101010’ button or press ‘Ctrl+K’ to format your code!

Thanks,

Scribe