This line is working perfect at ios 9 but when I try it on ios 8 its crashing and says
fatal error: unexpectedly found nil while unwrapping an Optional value
so what should I do for this. This is my code.
self.navigationController?.navigationBar.titleTextAttributes = [NSForegroundColorAttributeName:UIColor.blackColor(),NSFontAttributeName: UIFont(name: ".SFUIDisplay-Bold", size: 18)!]