//1.向数组插入数据
[self.allCitiesaddObject:@"上海"];
//向最后一行插入数据,前提一定要先将数据插入到数组中
NSIndexPath*indexPath = [NSIndexPathindexPathForRow:self.allCities.count-1inSection:0];
[self.tableViewinsertRowsAtIndexPaths:@[indexPath]withRowAnimation:UITableViewRowAnimationLeft]