Question

I am a problem with counting values in a plist file ,the problem is the if statement should check if the value is greater than objects in my plist , then stop moving to next pages , here is my code but :

    picturesDictionary = [NSDictionary dictionaryWithContentsOfFile:
                                    [[NSBundle mainBundle] pathForResource:@"images" ofType:@"plist"]];  
arrays = [picturesDictionary objectForKey:@"PhotosArray"];

    int photoCount =  [arrays count];


if ((photoNumber < 1) || (photoNumber > photoCount)) return nil;

controller = [BookController rotatableViewController];

PhotosInAlbum.image = [UIImage imageNamed:[arrays objectAtIndex:pageNumber]];

but after when photos reach to the last page , application will crash , debugger message :

'NSRangeException', reason: '-[__NSCFArray objectAtIndex:]: index (30) beyond bounds (30)'
*** First throw call stack:

Answer 1

try

if ((pageNumber < 0) || (pageNumber > (photoCount-1))) return nil;

the reason it crashes is, that count will give the number of objects, but when accessing each, you start with 0, so [array count]-1 is the last index.