-save id to the user default by using login button
let id = UserDefaults.standard
id.set(data.id , forKey : "ID")
id.synchronize
- using user id with this code in diferent pages
let user_id = UserDefaults.standard.integer(forKey : "ID")
- delete id from user default by using logout button
UserDefaults.standard.removeObject(forKey : "ID")
userDefaults.synchronize
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let mainScreen = UIStoryboard.init(name : "Main" , bundle : nil).instantiateViewController(withIdentifier :"BG")
appDelegate.window?.rootViewController =   mainScreen