2D dynamic array using ArrayList in Java

Question

I need to implement a 2D dynamic array. The number of rows is fixed, say n. But the number of columns for each row is not fixed and equivalent. For instance, the first row h

Answer 1

You could create an array of ArrayList elements because your row count is fixed.

ArrayList[] dynamicArray = new ArrayList[n]();

Note: You'll need to allocate an ArrayList object in each entry in the array. So...

for (int loop = 0; loop < n; loop++)
dynamicArray[loop] = new ArrayList();

OR if you'd like both rows and columns to be dynamic you could create an ArrayList of ArrayLists....

ArrayList> dynamicArray = new ArrayList>();

Once again, you'll need to create an array list in each new entry to dynamicArray.