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

Reynhart de Beer
Reynhart de Beer
1,854 Points
Posted by Reynhart de Beer
Reynhart de Beer
1,854 Points

What am i doing wrong in the challenge ?

Please can you guys help, see my code below. Not sure what to do..

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

}

func bookType (dict: [String : String]) -> Book? { guard let title = dict["title"], let author = dict["author"] else { return nil }

let price = dict["price"]
let pubDate = dict["pubDate"]

return Book(title: title, author: author, price: price, pubDate: pubDate)

}

let myBook = Book(title: "Steve", author: "Rey", price: "R500", pubDate: "Today")

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

}

func bookType (dict: [String : String]) -> Book? {
    guard let title = dict["title"], let author = dict["author"] else {
        return nil
    }

    let price = dict["price"]
    let pubDate = dict["pubDate"]

    return Book(title: title, author: author, price: price, pubDate: pubDate)
}

let myBook = Book(title: "Steve", author: "Rey", price: "R500", pubDate: "Today")

1 Answer

Moritz Lang
Moritz Lang
25,909 Points
Moritz Lang
Moritz Lang
25,909 Points

Hi Reynhart de Beer, I went through the challenge linked to this question. Isn't the question to write a failable initializer? Why did you wrote the bookType function? This is my solution for the challenge. Fell free to use early exit with a guard-statement instead of the if-let that I wrote. :)

struct Book {
    let title: String
    let author: String
    let price: String?
    let pubDate: String?
    init?(dict: [String: String]) {
      if let title = dict["title"], let author = dict["author"] {
        self.title = title
        self.author = author
        self.price = dict["price"]
        self.pubDate = dict["pubDate"]
      } else {
        return nil
      }
    }
}
Reynhart de Beer
Reynhart de Beer
1,854 Points
Reynhart de Beer
Reynhart de Beer
1,854 Points

Thanks for helping, seems to work.

I still need to wrap my head around swift :)