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Start your free trialPatrick Duhamel
5,786 PointsFailable initializer task is missing something, but Playground or Preview mode doesn't give me a hint on the issue...
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"],
let price = dict["price"],
let pubDate = dict["pubDate"] {
self.author = author
self.title = title
self.price = price
self.pubDate = pubDate
} else {
return nil
}
}
}
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"],
let price = dict["price"],
let pubDate = dict["pubDate"] {
self.author = author
self.title = title
self.price = price
self.pubDate = pubDate
} else {
return nil
}
}
}
1 Answer
Joshua Hawthorne
18,523 PointsNotice that "price" and "pubDate" in the Book struct are actually optionals. These values are allowed to be nil. In other words, price and pubDate can both be nil, and as long as title and author are valid we can create the instance of the struct. Your code should like like this (note that I am using guard statements, not if-let):
struct Book {
let title: String
let author: String
let price: String?
let pubDate: String?
init?(dict: [String : String]) {
guard let title = dict["title"] else { return nil }
guard let author = dict["author"] else { return nil }
if let p = dict["price"] {
self.price = p
} else {
self.price = nil
}
if let pubDate = dict["pubDate"] {
self.pubDate = pubDate
} else {
self.pubDate = nil
}
self.title = title
self.author = author
}
}