Error separating children from parent

I can not understand why the error occurs.

I am trying to separate all children from a parent, but an error appears:

UnityException: Transform child out of bounds.

The Scripting API says that:
"If the transform has no child, or the index argument has a value greater than the number of children then an error will be generated. In this case" Transform child out of bounds "error will be given"

But i used transform.childCount and going beyond should not occur. I have 240 children, when the process reaches 119, this error occurs. Some of the children are separated, some remain in the parent. The process just stops in the middle.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class Test1 : MonoBehaviour {
6.  
7.     public Transform parentTrans;
8.  
9.     void Start ()
10.     {
11.         int childsCount = parentTrans.childCount;
12.         Debug.Log(childsCount);
13.    
14.         for (int i = 0; i < childsCount; i++)
15.         {
16.             Transform child = parentTrans.GetChild(i);
17.             child.parent = null;
18.             Debug.Log(i);
19.         }
20.         Destroy(parentTrans.gameObject);
21.     }
22. }
23.  

 

The problem is you are looping through the children and removing them from the front instead of the back. Think of it this way. You have 10 children, so your count is 10. You remove the first child, which shifts everything. So the child in index 9 is now in index 8, but your for loop still tries to go to index 9. Children is just a collection under it's parent, so it behaves just like a list.

Just change your for loop

Code (CSharp):

1. for(int i = childsCount-1;i>= 0;i--)

Which will start you at the last child and work your way back.

 

Thank you.