I want to get back data in \"requestActive\" in \"User\" on Parse.t
I try this :
var user = PFUser()
var requestActive = user[\"requestActive\"]
<         
        You are declaring user at the top level of your view controller.
But then, still at the root level, you try to use it with user["requestActive"]: you can't do that.
You have to use user in a method, for example viewDidLoad.
So let's say the type of user["requestActive"] would be a String (just for the example), you would do something like:
var user = PFUser()
var requestActive: String?
override func viewDidLoad() {
    super.viewDidLoad()
    requestActive = user["requestActive"]
}
Of course, you have to replace String with your actual type.