Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSCFString nric]:

I get this error when i play with the searchbar that I have just implemented.. Some letters work while others will crash with the error in the title. The error seems to be here but i cannot figure out what is wrong with it : "cell.textLabel.text = info.nric;".

Someone please help =(

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

    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
    }

    // Set up the cell...

    if(searching){
        PatientInfo *info = [copyListOfItems objec开发者_如何学JAVAtAtIndex:indexPath.row];
        cell.textLabel.text = info.nric;
        cell.detailTextLabel.text = [NSString stringWithFormat:@"%i, %i", info.category, info.age];
    }
    else {

        //First get the dictionary object
        NSDictionary *dictionary = [listOfItems objectAtIndex:indexPath.section];
        NSArray *array = [dictionary objectForKey:@"Patients"];
        PatientInfo *info = [array objectAtIndex:indexPath.row];
        // NSString *cellValue = [array objectAtIndex:indexPath.row];
        cell.textLabel.text = info.nric;
        cell.detailTextLabel.text = [NSString stringWithFormat:@"%i, %i", info.category, info.age];
    }

    return cell;
}

One of the arrays that you think contains only PatientInfo objects actually contains an NSString. So when you then write info.nric, it's asking that NSString for its nric property, which of course doesn't exist. The actual error would be wherever you're mistakenly putting a string in the array (either copyListOfItems or listOfItems).

Replace with the following code, you will know what exactly is going wrong in your code:

PatientInfo *info = [copyListOfItems objectAtIndex:indexPath.row];
if((nil != info) && ([info isKindOfClass:[PatientInfo class]))
{
    if([info respondsToSelector:@selector(nric)])
    {
        cell.textLabel.text = info.nric;
    }
}