Downcasting in Swift with as and as?

Question

What\'s the difference between these two code snippets:

let cell = tableView.dequeueReusableCellWithIdentifier(\"cellId\") as UITableViewCell?
// vs
let cell         


        

Answer 1

The difference between, as and as?

• as? UITableViewCell means when you don't know what you're downcasting, you are assuming that as a UITableViewCell, but it might me Integer or Float or Array or Dictionary.

• as UITableViewCell? means it's an Optional Value, it may either contain a UITableViewCell or Nil value.