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iOS Object-Oriented Swift Complex Data Structures Custom Initializers

Posted by Pino Gatto
Pino Gatto
2,463 Points

Object-Orient Swift last task Help - Can't figure out what I'm doing wrong

Getting this error swift_lint.swift:23:30: error: cannot use instance member 'red' within property initializer; property initializers run before 'self' is available

structs.swift 
struct RGBColor {
  let red: Double
  let green: Double
  let blue: Double
  let alpha: Double



  // Add your code below
  init(red: Double, green: Double, blue: Double, alpha: Double) {
    self.red = red
    self.green = green
    self.blue = blue
    self.alpha = alpha

  }

   let description = "red: \(red), green: \(green), blue: \(blue), alpha: \(alpha)" 
}

2 Answers

tromben98
tromben98
13,273 Points
tromben98
tromben98
13,273 Points

Hi Pino!

You probably removed the description property unintentionally, because when you start the challenge it starts with a description property in the struct.

Here is the solution:

struct RGBColor {
    let red: Double
    let green: Double
    let blue: Double
    let alpha: Double

    let description: String

    // Add your code below
    init(red: Double, green: Double, blue: Double, alpha: Double) {

        self.red = red
        self.green = green
        self.blue = blue
        self.alpha = alpha
        self.description = ("red: \(red), green: \(green), blue: \(blue), alpha: \(alpha)")

    }

}

Best regards, Jonas

Pino Gatto
Pino Gatto
2,463 Points
Pino Gatto
Pino Gatto
2,463 Points

Ahhh, yes I see what I did...

Instead of moving the description variable after the init, I was simply supposed to self.description.

What i don't understand, and my confusion came from the fact that the description variable was set as a constant (let) meaning I couldn't change it.

Does the init method allow for changing let variables in an object?