How to fill a two Dimensional ArrayList in java with Integers?

Question

I have to create a 2d array with unknown size. So I have decided to go with a 2d ArrayList the problem is I\'m not sure how to initialize such an array or store information.

Answer 1

  import java.util.*;
    public class ArrayListDS { 
        public static void main( String [] args ) { 

        ArrayList> row = new ArrayList>();

           Scanner sc = new Scanner(System.in);

           System.out.println("Enter the number of row: ");
           int n = sc.nextInt();

           for(int i = 0; i < n; i++){

               ArrayList col = new ArrayList();
               row.add(col);

           System.out.println("Enter the number of column: ");
           int m = sc.nextInt();

               for(int j = 0; j < m; j++){
                    col.add(sc.nextInt()); 
               }
               System.out.println();
           }
           System.out.println(row);
        }
    }