Nested Lists "Add" method problem

Questions & Answers
1

Hello there,

for reasons I need a List of Vector2-Lists:

List<List<Vector2>> occludedObjects;
	
void someInitFunction(){
    occludedObjects = new List<List<Vector2>>();
	List<Vector2> occludedPoints = new List<Vector2> ();
	occludedObjects.Add (occludedPoints);
}

Now when I add a new Vector2 to a sublist, every sublist will overwrite it’s content with this Vector2.
Clearing any sublist seems to clear the other sublists, too.
Here is how I’m trying to do things:

occludedObjects[0].Clear();
occludedObjects[0].Add (new Vector2(0f, 0f));
occludedObjects[0].Add (new Vector2(0f, 1f));

I guess I am missing some basic nested lists business :frowning:
If this is not the source of the problem, i will try and dig deeper into my script.

Help (especially noob friendly) is very, very appreciated!

2

This is adding the exact same list instance each time…

 List<Vector2> occludedPoints = new List<Vector2> ();
 occludedObjects.Add (occludedPoints);

They all point to the same object, so it doesn’t matter which object reference you use, it’s going to add to the same list. You need to create a new instance each time, so…

 occludedObject.Add(new List<Vector2>());

Now each list entry in occludedObjects will point to a separate instance.