I have an arraylist of arraylists having string[]s i.e.,
ArrayList<ArrayList> arraymain = new ArrayList<>();
ArrayList<String[]> arraysub = new ArrayList<>();
Now, adding the elements to arraysub,
arraysub.add(new String[]{"vary","unite"});
arraysub.add(new String[]{"new","old"});
I tried:
arraymain.get(0).get(0)[1];
But I'm getting an error : Array type expected; found 'java.lang.Object' How can I now retrieve the data(the string stored in the string[])?
Change the type of the inner ArrayList:
ArrayList<ArrayList<String[]>> arraymain = new ArrayList<>();
ArrayList<String[]> arraysub = new ArrayList<>();
This way arraymain.get(0).get(0) will return a String[] instead of an Object.
It would be even better if you declare the variables as Lists, instead of forcing a specific List implementation:
List<List<String[]>> arraymain = new ArrayList<>();
List<String[]> arraysub = new ArrayList<>();
But arraymain accepts arraylists of type string array only, If u want to store different arraylists of different array types in arraymain then this will be the solution:
ArrayList<ArrayList<Object[]>> arraymain = new ArrayList<ArrayList<Object[]>>();
ArrayList<Object[]> arraysub = new ArrayList<Object[]>();
arraysub.add(new String[]{"kk"});
arraymain.add(arraysub);
ArrayList<Object[]> arraysub2 = new ArrayList<Object[]>();
arraysub2.add(new Integer[]{1,2});
arraymain.add(arraysub2);
ArrayList<ArrayList<String>> outer = new ArrayList<ArrayList<String>>();
ArrayList<String> inner = new ArrayList();
inner.add("ABC");
inner.add("XYZ");
inner.add("CDF");
outer.add(inner);
ArrayList<String> orderList = outer.get(0);
String first = orderList.get(0);
String second = orderList.get(1);
String third = orderList.get(2);
System.out.println("FirstValue: "+first);
System.out.println("SecondValue: "+second);
System.out.println("ThirdValue: "+third);
