removeObjectsInArray returning zero array when it shouldn't

Question

I am having issues with removeObjectsInArray returning an array with zero objects. The two arrays are different in size by 1 to begin with.

The code below is creating an array of all my contacts phone numbers.

        NSMutableDictionary *dOfPerson=[NSMutableDictionary dictionary];

        ABRecordRef ref = CFArrayGetValueAtIndex(allPeopleMutable,i);
        ABMultiValueRef phones =(__bridge ABMultiValueRef)((__bridge NSString*)ABRecordCopyValue(ref, kABPersonPhoneProperty));

        for(CFIndex i = 0; i < ABMultiValueGetCount(phones); i++) {
        mobileLabel = (__bridge NSString*)ABMultiValueCopyLabelAtIndex(phones, i);
        if([mobileLabel isEqualToString:(NSString *)kABPersonPhoneMobileLabel])
        {
            [dOfPerson setObject:(__bridge NSString*)ABMultiValueCopyValueAtIndex(phones, i) forKey:@"Phone"];
        }
        else if ([mobileLabel isEqualToString:(NSString*)kABPersonPhoneIPhoneLabel])
        {
            [dOfPerson setObject:(__bridge NSString*)ABMultiValueCopyValueAtIndex(phones, i) forKey:@"Phone"];
            break ;
        }

    }

    [contactListNumbersArray addObject:[dOfPerson objectForKey:@"Phone"]];

I am then saving this array to the NSUserDefaults outside the function that pulls the phone numbers. So it doesn't save the phone numbers everytime immediately.

    userDefaultArray = contactListNumbersArray;
    [defaults setObject:userDefaultArray forKey:@"allContactsNumberArray"];

I then go into the address book on my phone and add a contact. When it comes back in it realizes that my saved NSUserDefault is no longer the same as my address book. It redefines contactListNumbersArray (not the NSUserDefault) through the code above.

I then wanted to determine exactly what had changed so this is the code I was using.

        NSMutableArray *tempDiffArray = [[NSMutableArray alloc] init];

        tempDiffArray = [NSMutableArray arrayWithArray:contactListNumbersArray];

        [tempDiffArray removeObjectsInArray:userDefaultArray];

I got this working for the address book names, but the phone numbers are giving me issues. For instance 1 array will be size 403, the other 402, and I end up with a zero array.

Answer 1

The method removeObjectsInArray: will remove multiple occurrences of the same value. That your code works for names but fails for phone numbers suggests you have two or more names with the same number.