Question

This is yet another EXC_BAD_ACCESS question. Although I’ve done my homework and am certain that I am not over-releasing my NSArray.

So here is a snippet of my code:

tableData = [NSDictionary dictionaryWithJSONString:JSONstring error:&error];
//Collect Information from JSON String into Dictionary. Value returns a mutli 
dimensional NSDictionary. Eg: { value => { value => "null"}, etc }

NSMutableArray *t_info = [[NSMutableArray alloc] init];
for(id theKey in tableData)
{
    NSDictionary *get = [tableData objectForKey:theKey];
    [t_info addObject:get];
    [get release];
} // converting into an NSArray for use in a UITableView

NSLog(@"%@", t_info);
//This returns an Array with the NSDictionary's as an Object in each row. Returns fine

if (tvc == nil)
{
    tvc = [[tableViewController alloc] init]; //Create Table Controller
    tableView.delegate = tvc;
    tableView.dataSource = tvc;
    tvc.tableView = self.tableView;
    tvc.tableData = t_info; //pass our data to the tvc class
    [tvc.tableView reloadData];
}
...

Now in my TableViewController Class:

@implementation tableViewController
@synthesize tableData, tableView;

- (NSInteger) tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section 
{
    return [tableData count]; //Returns X Amount Fine.
}

- (UITableViewCell *)tableView:(UITableView *)the_tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{

    NSString *MyIdentifier = [NSString stringWithFormat:@"MyIdentifier"];

    UITableViewCell *cell = [the_tableView dequeueReusableCellWithIdentifier:MyIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:MyIdentifier] autorelease];
    }

    NSLog(@"%@", tableData); //** CRASHES!!**
    cell.textLabel.text = @"This is a test";
    return cell;
}

If I were to comment out that NSLog, it’ll work fine and return “this is a test” on each table row.

This one has really got me stumped, all the articles I have around about this problem is generally related to retain/memory issues.

Also, another important point.
If I were to pass through my original (NSDictionary) tableData from my first class code and run the same script in my tableViewController – I can NSLog the object perfectly fine.

Answer 1

The only time you need to release an object is if you have explicitly allocated it by way of new, alloc, or copy.

NSMutableArray *t_info = [[NSMutableArray alloc] init];
for(id theKey in tableData)
{
    NSDictionary *get = [tableData objectForKey:theKey];
    [t_info addObject:get];
    [get release];
}

You shouldn’t be releasing get here. By doing this, you’re releasing the reference that the tableData dictionary is holding onto, which is bad. My guess is that this is what is causing the problem that you’re encountering.

If I’m not mistaken, the reason why [tableData count] returns the expected value is because the array is still holding onto the references that have been released.