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iOS Object-Oriented Swift 2.0 Complex Data Structures Custom Initializers

Posted by Heath Robertson
Heath Robertson
Courses Plus Student 2,757 Points

Need Help | Custom Initialisers Code Challenge | Object Oriented Swift 2.0

What am I Missing?

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, description: String) {
    self.red = red
    self.green = green
    self.blue = blue
    self.alpha = alpha
Heath Robertson
Heath Robertson
Courses Plus Student 2,757 Points

Thanks

2 Answers

Nathan Tallack
Nathan Tallack
22,159 Points
Nathan Tallack
Nathan Tallack
22,159 Points

Hi Heath,

What we are doing here is taking the rgba values into the init function and computing the description from them. Take a look at your modified code below.

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

    let description: String

    // Not passing in description here, because we compute it within.
    init(red: Double, green: Double, blue: Double, alpha: Double) {
        self.red = red
        self.green = green
        self.blue = blue
        self.alpha = alpha

        // Computing description using interpolation of rgba values.
        description = "red: \(red), green: \(green), blue: \(blue), alpha: \(alpha)"
    }
}

I hope this helps clear it up for you. :)

Steven Deutsch
Steven Deutsch
21,046 Points
Steven Deutsch
Steven Deutsch
21,046 Points

Hey Heath Robertson,

Let's clear up a few things here. First, you have to remove the description parameter from your init() method. You will initialize the value of description using string interpolation and the values for red, green, blue, and alpha that you passed into the init() method. The init() method has access to the description property in the RGB struct because it is within it's scope (the method is nested inside of the struct).

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)"
}

Hope this helps. I think I did a poor job of explaining but ultimately led you to the correct result.