Re: question
Lew wrote:
And you haven't answered why the map is
Map <Integer, ArrayList <<String>>
instead of
Map <Integer, List <Integer>>
. Why is it so necessary to store Strings in the List, and ArrayLists in
the Map?
Daniel Moyne wrote:
Again Lew the code provided he is not the whyole code of my application ; it
is only somehow just alike to clearly expose my problem which was
successful done as the readers have provided the fix ; in this context the
whole code was not relevant ; in my acctual application I am reading
strings in a text file line by line ; each line contains strings separated
by coma ; when I read the file I store the strings in an ArrayList and this
ArrayList as the value of the map record with the line number as the key.
This does not explain why the choice of ArrayList as the generic type instead
of List.
I store the strings for later process that I do not want to initiate unless
whole data of my file is proved to be correct (data is supposed to have
some particular meaning) ; if the data is ok then I proceed by iterating
the map basically loop 2 of my example.
Daniel.
Your explanation doesn't cover why you need ArrayList specifically, as opposed
to using List as the compile-time type. Usually it's better to declare
variables as the interface type rather than a specific implementation.
Likewise, it's often easier to use Integer in a collection instead of
incurring the overhead of conversion to String, if the item being stored is an
integer, as it was in your example.
Obviously my question doesn't pertain to "the whole code of [your]
application" but to the specific examples that you posted. I am not curious
about your application, only about the practices you showed us.
I was curious why you were deviating from those practices, is all. You don't
have to explain, but I am curious still.
--
Lew