Question

I want to load a series of objects to an ArrayList, and return the index of where it was added so it can be used later directly from the ArrayList. It’d be akin to me loading a set of 5 frames for a graphic and calling the data for frame 3 directly from the list.
Upon looking around at a couple potential posts that may be related, I found something that was related, and made me wonder. Is there even a built in function to GET the index of a recently added object?

The link I am looking at that made me think of this was: ArrayList indexOf() returns wrong index?

Basically, the way I was looking at it was that I would do something along the lines of the following psuedocode:

    private ArrayList<FrameData> mylistofframeshere = new ArrayList();
    FrameData Framenumberone = new FrameData(constructorblah goes in here);
    int wherediditgo = mylistofframeshere.add(Framenumberone);

Or I thought I could do something along the lines of

    mylistofframeshere.getindex(Framenumberone);

My backgrounds in coding are more procedural based at this point, so I am more used to knowing what the index is, just in order to place the data to begin with. I looked around at the oracle documentation as well, with findings something similar to the above link. Any suggestions??

EDIT : I’m going to add some extra clarification in here, because I really didn’t put enough effort into the example and explanation.

Another example of trying to use something like a direct index of a list would be if I had a set of tiles I wanted to use as terrain for a game or something. I would load a set of possible tiles for the area into a central ArrayList. Upon trying to place these tiles, I would just reference the pre-loaded object I have in my ArrayList in order to draw the appropriate bitmap/whatever.

I’m still a bit new to Java, so I’m willing to bet it’s just something simple I’m overlooking in the mechanics of using these datatypes. I’ll keep editing this until I get the explanation right.

Answer 1

When you add something to an ArrayList, it goes to the last available space. In other words:

List<FrameData> list = new ArrayList<FrameData>();
list.add(frame1);

FrameData frame = list.get(list.size() - 1); //frame == frame1

But I wonder why you would need to do that. If you explain more about what you are trying to achieve, there might be a different / better way to get to the same result.