Initialization of NSMutableArray in a loop

mavris · June 2011

I have an IBAction like this:


if([checkinArray count]!=0){
        [checkinArray removeAllObjects];
 }
loop{
    Checkin *checkinsA = [[Checkin alloc] init];
    .....
   [checkinArray addObject:checkinsA];
    [checkinsA release];

}

And when checkinArray is not empty I am getting exc bad access error and the app is crashing. What I am doing wrong here? What I am trying to do is to empty the array and then refill ti with updated data. PS. The checkin array is declared in .h and is initialized on viewdidload.

dljeffery · June 2011

Where are you crashing (are you stepping through the code?), and what does the crash log look like?

mavris · June 2011

Its crashing at [checkinArray removeallobjects ]; with ECD_BAD_ACCESS sometimes.

BrianSlick · June 2011

How do you create checkinArray?

And I don't see much point for this test:

if([checkinArray count]!=0){
        [checkinArray removeAllObjects];
 }

If it is already empty, then what does it matter if you remove the objects again? It's not like the operation will take that long. But if your most common situation involves a populated array, then all you've done is add a test in front of the operation that you really want to perform anyway. Test time + operation time > operation time, every time.

mavris · June 2011

BrianSlick;347012 said:
How do you create checkinArray?

And I don't see much point for this test:
if([checkinArray count]!=0){
        [checkinArray removeAllObjects];
 }
If it is already empty, then what does it matter if you remove the objects again? It's not like the operation will take that long. But if your most common situation involves a populated array, then all you've done is add a test in front of the operation that you really want to perform anyway. Test time + operation time > operation time, every time.

I am trying to updated the content of the array with new data. Thats why I am testing if is empty. If is not then I am adding the data.

mavris · June 2011

BrianSlick;347012 said:
How do you create checkinArray?

I am creating it in .h:
NSMutableArray *checkinArray;
....
@property (nonatomic, retain) NSMutableArray *checkinArray;

and initializing in viewdidload:

checkinArray = [[NSMutableArray alloc] init];

BrianSlick · June 2011

mavris;347111 said:
I am trying to updated the content of the array with new data. Thats why I am testing if is empty. If is not then I am adding the data.

So if it is not empty, you don't want new data?

mavris;347115 said:
I am creating it in .h:
NSMutableArray *checkinArray;
....
@property (nonatomic, retain) NSMutableArray *checkinArray;

and initializing in viewdidload:

checkinArray = [[NSMutableArray alloc] init];

Looks ok, although you aren't using your property. Are you changing this anywhere else? Error sounds like an over-release.

And you are declaring it in .h. You are creating it in viewDidLoad.

mavris · June 2011

BrianSlick;347136 said:
So if it is not empty, you don't want new data?

Looks ok, although you aren't using your property. Are you changing this anywhere else? Error sounds like an over-release.

And you are declaring it in .h. You are creating it in viewDidLoad.

what do you mean I am not using my property?
I am using it in another method:

Checkin *tempcheck2 = [checkinArray objectAtIndex:i];

but this should be autoreleased right? Also this method is finished before calling the [checkinArray removeAllobjects];

BrianSlick · June 2011

See the properties link in my signature. You aren't using it, you are using the instance variable.

Post the entire code for your IBAction. You have a typo in the first post anyway.

mavris · June 2011

N/A

baja_yu · June 2011

Isn't your Checkin class retaining it's attributes (it should)? in which case these would be leaks:


checkinsA.taggedName =[[NSMutableArray alloc] init];
checkinsA.taggedID =[[NSMutableArray alloc] init];

mavris · June 2011

I was releasing them at the end of the loop but I removed them to check if this is the reason of bad access error.

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