On a related, yet different note...

I run into this all the time where I need to iterate through an
NSMutableArray (or set, etc, etc) and remove some of the items.  My normal
pattern has been this:

NSMutableSet *removeSet = [[NSMutableSet alloc] init];
for(NSObject *foo in myArray) {
   if(needToRemoveFoo) {
      [removeSet addObject:foo];
   }
}
for(NSObject *foo in removeSet) {
   [myArray removeObject:foo];
}
[removeSet release];


If I have to do multiple passes at the objects in myArray, I'll sometimes do
[removeSet removeAllObjects] instead of [removeSet release] and reuse the
NSMutableSet object as necessary.

Would it be better in general to make a copy of myArray in this case and
remove the objects directly from myArray as I iterate over the copy?  Or are
the two methods generally equal in terms of performance and memory usage?

I am currently doing this on the iPhone, so I am concerned with my memory
and CPU usage more than I would be on the Mac.  I also happen to be doing
this once every 30th or 60th of a second as part of my update loop in a
game.

Thanks!

On Mon, Nov 30, 2009 at 2:36 PM, Nick Zitzmann <n...@chronosnet.com> wrote:

> What happens if you try enumerating on a copy of the sublayer array? That's
> what I usually do in this situation...
>

-- 
dennis
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