new list for each iteration ?

[nimo frey]

What is better ?

This:

version 1:

for (User u : users) {
List<Hobby> h = u.getHobbies();
}

or that:

version 2:

List<Hobby> h = new ArrayList<Hobby>();
for (User u : users) {
h = u.getHobbies();
}

In version 1, I declare a list for each iteration, In version 2, I only declare one list and overwrite it for each iteration - but the overall result is the same. Following the rule "Declare variables as close as possible to where they are used." (http://www.javaranch.com/styleLong.jsp#init), I have to use version 1, but in this case I am not sure.

[Darryl Burke]

No, you're not declaring one list and overwriting it, you're assigning a different List, the one returned from getHobbies(), in both cases. The only difference is that in the second code, the last assigned List is still available after the loop exits.

[Rob Spoor]

Which makes it not yet eligible for garbage collection, so unless you still need it after the loop you should declare it inside the loop.