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iOS Object-Oriented Swift 2.0 Complex Data Structures Custom Initializers

oliverchou
oliverchou
20,886 Points
Posted by oliverchou
oliverchou
20,886 Points

I couldn't figure out what's going on! Anyone help me?

I cannot distinguish between "self" properties and others. And I don't know wheher to put the "discription assinment" statement , in the "init" or create another "method" or simply inside the "struc"?

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, discription: String) {
        self.red = red
        self.green = green
        self.blue = blue
        self.alpha = alpha

        self.discription = "red: " + red + ",green: " + green + ",blue: " + blue + ",alpha: " + alpha
    }
}

2 Answers

Steve Hunter
Steve Hunter
57,712 Points

Hi there,

A couple of things - first, you don't want to pass the description in as a parameter to the init method. You create description within init. Second, spell description correctly - that'll stop confusion between the top of the struct and your init method.

Lastly, maybe consider using interpolation to construct your description string. That all looks like:

    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)"
    }

I hope that helps.

Steve.

Steve Hunter
Steve Hunter
57,712 Points

No problem! :+1:

Cory Norell
Cory Norell
10,613 Points

Steve, your answer to this question just helped me complete the code challenge, so thank you! I was running into issues - I thought I had tried everything - until i stopped including description as a parameter.

My question is, why do we create the description inside the init rather than passing it as a parameter?

Steve Hunter
Steve Hunter
57,712 Points

Hi Corey,

I'm glad my answer helped! :+1:

There is no need to pass in description as a parameter as it is made up of the other parameters. To pass it in would duplicate typing without adding anything.

Does that make sense?

Steve.

Cory Norell
Cory Norell
10,613 Points
Cory Norell
Cory Norell
10,613 Points

Ahhh, I see. That makes perfect sense when you explain it that way. Thank you Steve!

Steve Hunter
Steve Hunter
57,712 Points

No problem! :smile: