Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

iOS Object-Oriented Swift Complex Data Structures Custom Initializers

Posted by NACHO MERINO
NACHO MERINO
1,216 Points

Code challenge init, struct, method

In the editor, I’ve declared a struct named RGBColor that models a color object in the RGB space.

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"

The error says that i'm not using the correct string interpolation. Don't understand what's going on.

Some help here!

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

  let description: String

  // Add your code below
  init custom ( red: Double, green: Double, blue: Double, alpha: Double, description: (String)) {
    self.red = 10.1
    self.green = 10.2
    self.blue = 10.3
    self.alpha = 0.5
    self.description = "red: \(red), green: \(green), blue: \(blue), alpha: \(alpha)"
   } 
}

1 Answer

Matthew Long
Matthew Long
28,407 Points
Matthew Long
Matthew Long
28,407 Points

Looks like you're really close. You tried giving your init method a name though? So remove custom after init. Next, you don't need to include description: String as a parameter, we are creating the description with the other parameters.

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

  let description: String

  init (red: Double, green: Double, blue: Double, alpha: Double) {
    self.red = 10.1
    self.green = 10.2
    self.blue = 10.3
    self.alpha = 0.5

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

Also, you didn't have to give it default values:

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)"
 }

var myColor = RGBColor(red: 10.1, green: 10.2, blue: 10.3, alpha: 0.5)
NACHO MERINO
NACHO MERINO
1,216 Points

thanks mate! it works now