How to know the total number of a group of differently tagged objects in the Level?

I have a bunch of collectables in my levels but they have different Tags ("collectableTypeA", "collectableTypeB" etc, there are 6 different types of them).

I want to know each moment, how many collectables (not of a specific type, I want the total number) I've got left.

Which would be the best way to put the number of the collectalbes in a variable? Basically, I want to go to the next level when I collect all of them, by using something like:

if (numberOfCollectables) ==0 {
Application.LoadLevel(Application.loadedLevel + 1);
}

Well, you could use:

gameObject[] colA = GameObject.FindGameObjectsWithTag("collectableTypeA");

http://unity3d.com/support/documentation/ScriptReference/GameObject.FindGameObjectsWithTag.html

However, I create a list containing all collectables and then remove a collectable item from the list, when needing to. Because then you didn't need to use the above method and you could then just use `.Count` to get the total number of objects in the list.

You should create a static list that gets added to and items removed from, this would be a lot better then calling FindGameObjectsWithTag all the time, evaluation of all the objects seems like a waste of ticks.

If you're using a static list and your Collectible types are actually a type, use the reference of the attached object to remove it from the list either using IndexOf which is a member of Lists.