Question

I try understand what happens from some tutorials but unfortunately I am not found the answer.
I think that the problem may be that i didn’t have IF in case that I get nil in search result.

the error is:
‘NSRangeException’, reason: ‘* -[__NSArrayM objectAtIndex:]: index 0 beyond bounds for empty array’

I use that method:

- (void)filterContentForSearchText:(NSString*)searchText scope:(NSString*)scope
{
    //removes previos search result
    [[self searchResults]removeAllObjects];

    for (Books *book in [self.fetchResultsController fetchedObjects])
    {
            if([self searchResults] != nil)
            {
                NSComparisonResult result = [book.title compare:searchText
                                                   options:(NSCaseInsensitiveSearch|NSDiacriticInsensitiveSearch)
                                                     range:NSMakeRange(0, [searchText length])];
                if (result == NSOrderedSame )
                {
                        [self.searchResults addObject:book];
                }
            }
        }
}

also can find my full project at the git:
https://github.com/dennis87/git_bookList

edit:
when I try put if like this one

if ([scope isEqualToString:@”All”] || [book.title isEqualToString:scope])

the app crush without let me press any thing..

Answer 1

The problem is that numberOfSectionsInTableView always returns 1 for the search results table, even if there are no search results. The crash happens in titleForHeaderInSection:

return [[[self searchResults] objectAtIndex:section] author];

because the object at index 0 is accessed from an empty array.

So either you change numberOfSectionsInTableView to return 0 if the search results array is empty, or you change titleForHeaderInSection to return something different for the search results table.