ios - Set view controllers of UITabBarController in Swift -

i trying programatically set view controllers of custom tabbarcontroller:

import uikit  class tabbarviewcontroller: uitabbarcontroller, uitabbarcontrollerdelegate {  var cameraviewcontroller: uiviewcontroller? var profileviewcontroller: uiviewcontroller?  override func viewdidload() {     super.viewdidload()      self.delegate = self       //self.viewcontrollers = [cameraviewcontroller, profileviewcontroller] as! [anyobject]?     let controllers: [uiviewcontroller?] = [cameraviewcontroller, profileviewcontroller]     self.setviewcontrollers(controllers as! [anyobject], animated: true)  } 

but line

self.viewcontrollers = [cameraviewcontroller, profileviewcontroller] as! [anyobject]? 

i error cannot convert [uiviewcontroller] [anyobject?]

and line

self.setviewcontrollers(controllers as! [anyobject], animated: true) 

i error saying:

cannot invoke 'setviewcontrollers' argument list of type '([anyobject], animated: bool)' 

my problem anyobject , typecasting guess.

the problem view controllers trying use declared optional:

var cameraviewcontroller: uiviewcontroller? var profileviewcontroller: uiviewcontroller? 

so have 3 options:

• don't make them optional. requires initialize them when initalize tabbarviewcontroller. maybe safest option.

• if know cameraviewcontroller , profileviewcontroller never nil in viewdidload:

  self.viewcontrollers = [cameraviewcontroller!, profileviewcontroller!] 

• check if cameraviewcontroller , profileviewcontroller not nil in viewdidload. smells bad design me though.

  if let c = cameraviewcontroller, let p = profileviewcontroller {     self.viewcontrollers = [c, p] } 

so boils down how initialize cameraviewcontroller , profileviewcontroller. set before tab bar view controllers shown? if so, recommend adding custom init class.