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iOS Protocols in Swift Protocol Basics Protocols With Methods

vivek d
seal-mask
.a{fill-rule:evenodd;}techdegree
vivek d
iOS Development Techdegree Student 1,596 Points

how to write the function ?

how to write the func to change color?

protocols.swift
// Declare protocol here
protocol ColorSwitchable {
    func switchColor(_ color: Color)

}

enum LightState {
  case on, off
}

enum Color {
  case rgb(Double, Double, Double, Double)
  case hsb(Double, Double, Double, Double)
}

class WifiLamp {
  var state: LightState
  var color: Color

  init() {
    self.state = .on
    self.color = .rgb(0,0,0,0)

     func switchColor(_ color: Color) {
        color = .hsb(0, 0, 0, 0)
    }
  }
}

1 Answer

Matthew Long
Matthew Long
28,381 Points

You've almost got it, but for a couple things. First off, the switchColor method doesn't need to be inside init method. Secondly, and perhaps what is most confusing, you need to set the color of the lamp to the color that is passed in. Do this with self:

protocol ColorSwitchable {
  func switchColor (_ color: Color)
}

enum LightState {
  case on, off
}

enum Color {
  case rgb(Double, Double, Double, Double)
  case hsb(Double, Double, Double, Double)
}

class WifiLamp: ColorSwitchable {
  let state: LightState
  var color: Color

  func switchColor(_ color: Color) {
    // set lamps color to the local argument color
    self.color = color
  }

  init() {
    self.state = .on
    self.color = .rgb(0,0,0,0)
  }
}