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iOS Object-Oriented Swift Complex Data Structures Custom Initializers

India Poetzscher
PLUS
India Poetzscher
Courses Plus Student 3,821 Points

I'm stuck and I can't figure this out!

Your task is to write a custom initializer method for the object. Using the initializer assign values to the first four properties. Using the values assigned to those properties create a value for the description property that is a string representation of the color object.

For example, given the values 86.0 for red, 191.0 for green, 131.0 for blue and 1.0 for alpha, each of the stored properties should hold these values and the description property should look like this:

"red: 86.0, green: 191.0, blue: 131.0, alpha: 1.0"

structs.swift
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

  }

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

3 Answers

You're on the right track but there are a couple problems with your code.

First problem is that you are assigning the value to the description variable outside of the init constructor. This can be seen in the error message in the output console

swift_lint.swift:24:1: error: expected declaration

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

^

The next problem is with the interpolation itself. The challenge wants something along the lines of this:

description = "red: \(value), green: \(value) ..." etc

But you have tried to just interpolate all of the variables and their type instead. If you make these changes it should pass fine

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
    description = "red: \(red), green: \(green), blue: \(blue), alpha: \(alpha)"
  }
}
Steven Parker
Steven Parker
208,474 Points

You're pretty close! But the description should be set inside the "init" method with the other properties.

Also, you'll need to use literals for each property name in addition to the property values to get it to look like what the instructions asked for (like "red: \(red), " ... etc.).