填充tableview时，我的应用程序崩溃，因为它声称属性为零，但在我设置它之前打印该属性表示它有一个值

I am searching through a database of usernames with a search bar and updating the tableview's database of User() accordingly. The search updates the array fine, but my app crashes when I the tableview tries to change its own label to the first name of the User() because it claims that firstName is nil. I know for a fact that it is not nil, though. RIGHT before it tries to update the label, I print the object's property and it prints the correct username. I have no clue what I'm doing wrong. Here's the code... I am searching through a database of usernames