Why does one arraylist change when a copy of it is modified

Question

Its probably a very simple one but its\' still confusing me!

import java.util.ArrayList;

public class Sample {
    ArrayList i = new ArrayLis         


        

Answer 1

You created a memory stage for j with ; j = new ArrayList<>();
but then you said that let j refer to i's memory stage. So after j=i; any changes on i or j are going to effect both of them. Because they reference to the same objects.