Remove object from an array stored in a singleton - objective-c

Question

Im working with a singleton to store some data, her's the implementation
static ApplicationData *sharedData = nil;
#implementation ApplicationData
#synthesize list;
+ (id)sharedData
{
static dispatch_once_t dis;
dispatch_once(&dis, ^{
if (sharedData == nil) sharedData = [[self alloc] init];
});
return sharedData;
}
- (id)init
{
if (self = [super init])
{
list = [[NSMutableArray alloc]init];
}
return self;
}
if list have less than 3 (2<) object i the app crash with "index 0 beyond bounds for empty array"
// NSMutableArray *anArray = [[NSMutableArray alloc]initWithObjects:#"", nil];
while ([[[ApplicationData sharedData]list] lastObject] != nil)
{
File *file = [[[ApplicationData sharedData]list] lastObject];
BOOL isDir;
if (![[NSFileManager defaultManager] fileExistsAtPath:file.filePath isDirectory:&isDir])
{
NSMutableDictionary *tmpDic = [NSMutableDictionary dictionaryWithObjects:[NSArray arrayWithObjects:file.fileName,file.filePath,logEnteryErrorfileNotFoundDisplayName,[formatter stringFromDate:[NSDate date]], nil] forKeys:[NSArray arrayWithObjects:logShredFileName,logShredFilePath,logShredStatue,logShredDate, nil]];
[logArray addObject:tmpDic];
errorOccured = YES;
[[[ApplicationData sharedData]list] removeLastObject];
continue;
}
... other code
}
if i use the anArray that work perfectly.
what is the problem ?

Answer 1

That's totally weird, you've probably did something else to achieve this. Why don't you use - (void)removeAllObjects?
Maybe you remove objects in the while cycle the last line, ie:
while ([[[ApplicationData sharedData]list] count] != 0)
{
// remove object from list
// ...
[[[ApplicationData sharedData]list] removeLastObject];
}
And just a note, you don't need to check if (sharedData == nil) in sharedData as far as it's guaranteed to be executed only once. (unless you do something outside to your static variable, but that's not how it's supposed to be done I believe)