UITableViewCell加载时的错误

static NSString *identifier = @"TypeTableViewCellIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier];
!!!!!!!! 注意cell的判断
if (cell) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier];
cell.backgroundColor = [UIColor whiteColor];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
cell.textLabel.text = [_arrTypes objectAtIndex:indexPath.row];

return cell;

}

注释:如果cell的判断写成上面那样,会报出下面的错误:
reason: UITableView (; layer = ; contentOffset: {0, 0}; contentSize: {200, 880}>) failed to obtain a cell from its dataSource (>)