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iOS

Anthia Tillbury
Anthia Tillbury
3,388 Points

Custom Initialisers Code Challenge (Object Orientated Swift)

My code compiles with wifi v3 and Xcode v8 in the Playground, but not on the website:

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

    let description: String

    // Add your code below

    init() {
        self.red = 86.0
        self.green = 191.0
        self.blue = 131.0
        self.alpha = 1.0

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

}



let colourTable = RGBColor.init()

colourTable.description

I would like confirmation if I have completed the challenge as demanded:

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"

ref: https://teamtreehouse.com/library/objectoriented-swift-2/complex-data-structures/custom-initializers

Thanks!

3 Answers

Hi James!

The reason your solution compiles in Xcode is because there is no errors with your code. However the solution does not provide what the code challenge is asking you to do.

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

let colour = RGBColour(red: 81.0, green: 181.0, blue: 243.0, alpha: 1.0)

You have set default values for the stored properties in RGBColor when you should be instead adding parameters for these in the initialiser method.

Init is also not a method you call upon an object. It essentially sets the values for all of the stored properties based on the arguments provided.

I would recommend comparing the solutions, and try again from memory after a few hours to fully make sure you understand and solidify your knowledge.

All the best!

Mitch

Anthia Tillbury
Anthia Tillbury
3,388 Points

I see immediately what I have done. I actually began writing out the properties in the Initialiser, comparing Initialised properties to .self, but then decided to declare them in the initialiser for some reason.

Thanks for your help!

Awesome! Always good to figure it out yourself.

No problem!

All the best,

Mitch