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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

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

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

Thanks for helping, seems to work.

I still need to wrap my head around swift :)