On 01/08/2015 03:24 AM, David Holmes wrote:
On 7/01/2015 7:45 PM, Remi Forax wrote:
A simple Java question, what this code does ?
ArrayList<String> list = new ArrayList<>();
list.add("foo");
list.add("bar");
for(String s: list) {
list.remove(s);
}
:(
Rémi
tip: the bug lies in ArrayList.Itr.hasNext() (and
AbstractList.Itr.hasNext()).
This is not a bug. The only supported way to remove from a collection
you are iterating over is to use an Iterator's remove method.
http://docs.oracle.com/javase/8/docs/api/java/util/Iterator.html#remove--
"The behavior of an iterator is unspecified if the underlying
collection is modified while the iteration is in progress in any way
other than by calling this method."
and as already pointed out the forEach docs make it clear you can't
use forEach in such a context as the Iterator is not exposed to you.
So don't do that.
Hi David,
while I agree that fail-fast behavior should be done on the best effort
basis,
i think like Paul said that the size should be stored in a field of the
iterator because
i don't see the point to try to support the fact that the size of the
collection
can change during the iteration.
so in my opinion, it's not a bug but the current implementation of
ArrayList.Itr should be changed
or maybe there is a case where supporting a size changed is valid ?
David
Rémi
