How to keep track of objects in an Array?

How to keep track of objects in an Array?

I need help in keeping track of objects in an array. I have tried giving
each object an arrayIndex var, so I can splice by getting that var which
represents the index in the Array.
object0.arrayIndex = 0;
object1.arrayIndex = 1;
object2.arrayIndex = 2;
object3.arrayIndex = 3;
But this is problematic if you move objects to different arrays. Objects
would move from different places and therefore the arrayIndex var needs to
be constantly updated.
I have done this by adding an static ID to each object. With a for loop I
check each object for the corresponding object ID I want to splice
var objectID:Number = objectArrayTarget.id;
for (var t:int; t<_objectArrayLayer1.length; t++)
{
if (objectID == _objectArrayLayer1[i].id)
{
var indexOfObject:Number =
(_objectArrayLayer1.indexOf(_objectArrayLayer1[i]));
}
}
_objectArrayLayer1.splice(indexOfObject, 1);
While this works is there a more efficient way of keeping track of objects
in an Array? With 100+ objects this might create some slowdown
P.S. These objects are getting spliced and then pushed to a new array.