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

Well, if you know you have 3 rows and 5 columns (as shown in your data example) you could initialize it as follows:

int[][] a = new int[3][5]; 

However, if the number of rows changes you could do something like this:

String dataStr = "0,1,0,1,0:0,1,1,0,1:0,0,0,1,0";

String[] rows = dataStr.split(":");

String[] cols = rows[0].split(",");

Now you can initialize:

int[][] a = new int[rows.length][cols.length];

This will accomodate changing row and col size. Might not be the most elegant approach but it should work.