Accessing ArrayList of an ArrayList

[sid0404]

Hi

How do I print elements of an ArrayList of an ArrayList, I think it has to be something similar to a 2 D array, but with a difference, my child arraylist has different number of elements say I have 3 child lists and they have 2, 5, 4 elements when I add them to the parent arrayList, but the number of elements in each child list can vary from time to time, can any one suggest a modular approach towards it ?

Clarification appreciated.

[JosAH]

Why not use the for-each loop? In the next example I assume that your inner
Lists contain Strings; have a look:

ArrayList<ArrayList<String>> outer= ...; // your outer list
for (List<String> inner : outer) // loop over outer list
   for(String str : inner) // loop over inner list
      // do something with str
 

Of course you can also use an old fashioned for loop:

ArrayList<ArrayList<String>> outer= ...; // your outer list
for (int i= 0, n= outer.size(); i < n; i++) { // loop over outer list
   List<String> inner= outer.get(i);
   for (j= 0, m= inner.size(); j < m; j++) {
      String str= inner.get(j);
      // do something with str
   }
}
 

Or you can user Iterators (left to the reader for an exercise)

kind regards,

Jos