check object type for UIButton - swift

Question

How can I verify the object type?
the goal is to check an object custom type to check the value
#IBAction func showAnswer(_ sender: UIButton) {
let question: Question = questions[currentQuestionIndex]
let rightAnswer = question.answers![question.answer]
let subViews = self.view.subviews
subViews.forEach { view in
if view.isMember(of: AnswerButton.self) {
let btn = view as! AnswerButton
if btn.titleLabel!.text == rightAnswer {
btn.hightlight()
}
}
}
}
this is the UI. the button with the right answer should highlight if this is the right answer.
enter image description here

Answer 1

Instead of
if view.isMember(of: AnswerButton.self) {
let btn = view as! AnswerButton
if btn.titleLabel!.text == rightAnswer {
btn.hightlight()
}
}
Use conditional downcasting:
if let btn = view as? AnswerButton {
// btn could be accessed as an instance of `AnswerButton` now
if btn.titleLabel!.text == rightAnswer {
btn.hightlight()
}
}
If you don't need to downcast the button then you can loop over the subviews with condition:
for view in subviews where view is AnswerButton {
// view is still treated as an instance of UIView but could be downcast to AnswerButton
}