How do I get the index of a 2d arraylist to be used in the ArrayList.set() method?

Question

I have a 2D ArrayList and I want to replace one of the elements with something else by using the set method.

According to the Java API:

set(int index, E Element)

is the constructor. How do I input the index, given that the ArrayList is 2D?

Answer 1

If you have a two-dimensional ArrayList , then what you need to do is

outerList.get(x).set(y, newValueAtXY);

...which gets the row at index x and sets element y in that row to newValueAtXY .

Answer 2

I came across this while searching:

array.get(i1).put(i2, value);

I think, it can be modified like this:

array.get(i1).set(i2, value);

I hope it works.