Remove a particular object from list on trigger exit

Question

Trying to remove a specific object from my list on trigger exit is prooving difficult for some reason. As you can see i've done everything i can to try to debug this using print and Debug.Break... i've narrowed it down to when comparing the GetInstanceID is failling. If removing objects from a list/array is it ok to iterate backwards through the list/array?

Some help would be greatly apreciated!

 function OnTriggerExit(other : Collider) {
 print(other.transform.GetInstanceID());
 
 if(other.transform.tag == "Cube")
     {
         if(cubeList.Count != 0)
             {print("iterating through Cube List");
                 for(var i : int = cubeList.Count-1; i >= 0; i--)
                     {    
                     print("in iteration loop");
                     var currentCubeObject : GameObject = cubeList[i];
                     print("the current cube ID " + currentCubeObject.GetInstanceID());
                         if(currentCubeObject.GetInstanceID() == other.transform.GetInstanceID())
                             {    cubeList.RemoveAt(i);    Debug.Break();}
                         if (i == cubeList.Count) {break;}
                     }
                 
                 //cubeList.RemoveAt(cubeList.Count-1);
                 //print("cube exited the colum " + transform.name);
                 //print("break for cube removal from " + transform.name);
                 //Debug.Break();
             }
     }
 }

Answer 1

Best Answer

Answer by Berenger · Mar 02, 2012 at 10:29 PM

You could use list.Remove(other). I suppose GameObject overrides Equals to compare instance ids. If it's too long, try looking only for the occurence index inside the loop (break out once you found it ) and remove after, sort of like that :

var index : int = -1;
for( var curr : GameObject in cubeList ){
    ++index;
    if( curr.GetInstanceID() == other.transform.GetInstanceID() )
        break;
}
if( index >= 0 && index < cubeList.Count )// ocurrence was found
    cubeList.RemoveAt(index);

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Drexster · Mar 02, 2012 at 10:43 PM 0

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Awesome. thank you very much, that works. *though change the cubeList.Length to be cubeList.Count :)

I still don't understand what was wrong with my solution however...

Berenger · Mar 02, 2012 at 11:45 PM 0

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Your code seems correct, you're making a remove during the loop but it's not using the enumerator, and you check the boundaries, so I don't now (edit on the code done, thanks)

Remove a particular object from list on trigger exit

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