swift - Unable to change protocol conformance of an object -


in code, wheeled , vehicle protocols, bike class conforms both of protocols

protocol wheeled {     var numberofwheels: int { } }  protocol vehicle {     var maker: string { }     var owner: string {get set}     var ownerkid: string { } }   class bike: vehicle, wheeled {     let numberofwheels: int = 0     var ownerkid: string = "junior"      var maker: string {         return "ford"     }      var owner: string {         {             return "bob"         }         set {             ownerkid = "\(newvalue) junior"         }     } }  let bike: bike = bike()  var thebike: vehicle = bike // #1 var thebike: wheeled = bike // #2 error: invalid redeclaration of 'thebike'

when check properties of thebike, in #1, thebike object has properties conform vehicle protocol; while in #2 thebike object has properties conform wheeled properties

therefore, feel thebike in #1 , #2 different, why tells me invalid redeclaration?

question: how should change protocol conformance of object? or allowed change conformance of object?

appreciate time , help.

  • you cannot declare variable (i.e. same name) twice.
  • if need access properties of protocol, use if let ... as? ... recast.

example:

if let thebike = thebike as? wheeled  {     print(thebike.numberofwheels) }

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