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Start your free trialAryaman Dhingra
3,536 PointsHow to unwrap optionals in initializers?
I can't figure out how to unwrap optionals that are inside initializers. Please help.
struct Book {
let title: String
let author: String
let price: String?
let pubDate: String?
init?(dictionary: [String: String]) {
self.title = dictionary["title"]
self.author = dictionary["author"]
let pubDate = dictionary["pubDate"]
let price = dictionary["price"]
self.pubDate = pubDate
self.price = price
}
}
1 Answer
Brandon Mahoney
iOS Development with Swift Techdegree Graduate 30,149 PointsDon't forget you need to use dict and not dictionary as per the instructions. Also you its title and author you need to be worried about in case they are not there.
With if let:
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
}
}
}
With a guard let:
struct Book {
let title: String
let author: String
let price: String?
let pubDate: String?
init?(dict: [String: String]) {
guard let title = dict["title"], let author = dict["author"] else {
return nil
}
self.title = title
self.author = author
self.price = dict["price"]
self.pubDate = dict["pubDate"]
}
}