How do you create a Two-Dimensional ArrayList?

Create a program that stores the square of the numbers 0, 1, 2 & 9 in an ArrayList of 10 elements.?

• For example, the third element which has an index of 2 should store 4.

• Answer:

  ArrayList<Integer> list = new ArrayList<Integer>(); list.add(0); list.add(1*=1); //A square is just a number times itself [ i*=i ] list.add(2*=2); list.add(9*=9); list.add(0); list.add(0); list.add(0); list.add(0); list.add(0); list.add(0); //This is for just 0, 1, 2, and 9. If you meant zero to nine then you do the same process for each Integer or variable. Which can be put into a loop: ArrayList<Integer> list = new ArrayList<Integer>(); Integer i = new Integer(0); for(i=0;i<10;i++) { list.add(i*=i); }