Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

iOS Swift 2.0 Enumerations and Optionals Introduction to Optionals Initializing Optional Values

ziakarim
ziakarim
20,779 Points

Error?

What is the error in the code below? Compiles in a playground, but not on treehouse. thx!

struct Book { let title: String let author: String let price: String? let pubDate: String?

init? (dict: Dictionary<String, String>) {
    guard let title = dict["title"], author = dict["author"] else {
        return nil
    }
    price = dict["price"]
    pubDate = dict["pubDate"]

    self.title = title
    self.author = author
}

}

optionals.swift
struct Book {
    let title: String
    let author: String
    let price: String?
    let pubDate: String?

}

1 Answer

Zia,

I believe the Dictionary definition as Dictionary<String, String> was the issue. I changed that to [String: String] and that passed.

struct Book {
    let title: String
    let author: String
    let price: String?
    let pubDate: String?

    init? (dict: [String: String]) {
        guard let title = dict["title"], author = dict["author"] else {
            return nil
        }
        price = dict["price"]
        pubDate = dict["pubDate"]

        self.title = title
        self.author = author
    }
}

Let me know if that works for you!

Florin

ziakarim
ziakarim
20,779 Points

Great, thanks Florin!