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Eris Ramirez
5,916 Points" Make sure that the initializer returns a valid instance given a valid dictionary "what this means?
I need to know what that Bummer! means so I can finish this code I have tried a bunch of differents codes but I still don't get it
struct Book {
let title: String
let author: String
let price: String?
let pubDate: String?
init?(dict: [String : String]){
self.title = "er"
self.author = "Eris Ramirez"
self.price = nil
self.pubDate = nil
return nil
}
}
let instance = ["title": "Los que ganan" , "author": "Eris Ramirez", "price": "150", "pubDate": "nil"]
Book(dict: instance)
3 Answers
tromben98
13,273 PointsHi Eris!
You need to configure your initializer using a guard statement. Then you can access the dictionary values using the right keys, for example: dict["title"].
Best regards, Jonas
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"]
}
}
let instance = ["title": "Los que ganan" , "author": "Eris Ramirez", "price": "150", "pubDate": "nil"]
Book(dict: instance)
Ignazio Calo
Courses Plus Student 1,819 PointsThe challenge is to write a "failable" initializer or, in other words, an initializer that can give you back a valid object or nil if something is wrong.
If you look at your code you're always returning nil no matter if the dict parameter is valid or not.
So what you need to do is to check if the dict contains the values that are required to create your Book, and return nil if one of the two values are missing, or return a valid object in the other case.
You also need to check only two fields on the dictionary, because only the title and author are mandatory, the other two properties price and pubDateare optional therefore even if you don't have any value inside the dictionary for those properties you can still return a valid object.
Of course the solution posted from tromben98 works fine, I just wanted add more context.
tromben98
13,273 PointsGood work Ignazio!
I wasn't sure how to express myself, Thanks!
Eris Ramirez
5,916 PointsThanks a lot to everyone It works perfectly