Re: App Crashing when remove an Object

FROM : Mario Gajardo Tassara
DATE : Sat Mar 29 18:52:42 2008

El 28-03-2008, a las 21:08, Sherm Pendley escribió:

> On Fri, Mar 28, 2008 at 8:49 PM, Andrew Farmer <<email_removed>> 
> wrote:
> On 28 Mar 08, at 18:37, Mario Gajardo Tassara wrote:
> > In a portion of code of my app (collision detection part) i need to
> > remove an object from an array of objects,
> > when two distinct objects crashed i decrement a life counter,  and
> > if this is equal to zero the object must be destroyed, but when the
> > counter
> > reach de zero and the object is destroyed my app crash. Some one can
> > help me with this problem, here is the code, and thanks in advance:
>
> You're removing an object from an array while iterating through it.
> Think carefully about what this is doing to the indexes of objects in
> the array, and you'll probably see what's going on.
>
> You probably ought to move to some sort of "mark-and-sweep" algorithm
> here, rather than mutating the array while iterating through it.
>
> No argument here.
>
> But, if you *do* want to mutate an array while iterating through it, 
> a common approach is to iterate through it backwards. That way, 
> deleting an element will only shift the elements at indexes you've 
> already touched.
>
> sherm--
>
>
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Following your recommendations, Im trying to implement a "mark-and-
sweep" solution to this problem, yesterday i did the backwards iterate 
aproach but my app still crashed. If someone have another solution 
please share with me, thanks.



Mario Gajardo Tassara
<email_removed>