When to create iterator for a list?

When to create iterator for a list?

Is it possible to do the following?
List<String> list = new ArrayList<String>();
Iterator<String> iterator = list.listIterator();
populateList(list);
I am creating a list and getting its iterator before populating the list
with data. Will I be able to get the elements of the list using the
iterator? Does the order of getting the iterator and populating the array
make any difference?
Any help will be appreciated.