Q:

How to create 2D ArrayList and add elements

I have a small program that hold pairs of states and their capitals in 2D array. Below this program:
public class StateCapitals {

public static void main(String[] args) {
    String[][] answers = {
            {"Alabama", "Montgomery"},
            {"Alaska", "Juneau"},
            {"Arizona", "Phoenix"},
            {"Arkansas", "Little Rock"},
            {"California", "Sacramento"},
            {"Colorado", "Denver"},
            {"Connecticut", "Hartford"},
            {"Delaware", "Dover"},
            {"Florida", "Tallahassee"},
            {"Georgia", "Atlanta"}
    };

    int correctCount = 0;

    for (int i = 0; i < answers.length; i++) {

        System.out.print("What is the capital of " + answers[i][0]);

        Scanner input = new Scanner(System.in);

        String userInput = input.nextLine();

        for (int j = 0; j < answers[i].length - 1; j++) {
            System.out.println("The correct answer should be " + answers[i][j + 1]);

            if(userInput.equals(answers[i][j + 1]))
                correctCount++;

        }

    }

    System.out.println("The correct count is " + correctCount);
    }
}

I need to replace regular 2D array with List<List<String>> super2dArray = new ArrayList<ArrayList<String>>(). 
I found some threads on stackoverflow how to add array that I want. Here is links: How to create an 2D ArrayList in java? andHow do I declare a 2D String arraylist?. But these discussions didn't explain how to add elements in each ArrayList. The best that I can do to create new ArrayList then add some elements and finally attached ArrayList to another one. They didn't explain how to add elements to 2D ArrayList.

A:

Here a way easier example :)
Notice that I give a fixed initial length to the constructor of the ArrayList as we already know the length of the array.
List<List<String>> myListOfListOfString = new ArrayList<List<String>>(answers.length);

for(String[] array : answers)
    myListOfListOfString.add(Arrays.asList(array));

See documentation for more details.

