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Start your free trialJohn Wilcox
4,233 PointsExtra argument in call?
Hi, I'm getting an 'extra argument author in call' error. I can't figure out why - author is unwrapped in the guard statement. The memberwise init does call for author. Any suggestions?
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
}
let price = dict["price"]
let pubDate = dict["pubDate"]
Book(title: title, author: author, price: price, pubDate: pubDate)
}
}
1 Answer
David Papandrew
8,386 PointsHi John,
You want to bind the values passed in as arguments to the init method to the Book properties. There's also an extraneous line of code in the init method with a class declaration and parameters. You should remove that.
Here's the corrected code:
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"]
}
}
John Wilcox
4,233 PointsJohn Wilcox
4,233 PointsBah, you're right. I see that I should have just assigned to the parameters directly. Thanks - sometimes I truly think I'm dyslexic when it comes to code.
What do you mean when you said "There's also an extraneous line of code in the init method with a class declaration and parameters." I see I can omit the underscore before the word dict. Otherwise however, to my eyes our guard statements look alike.
David Papandrew
8,386 PointsDavid Papandrew
8,386 PointsHi John,
The line I was referring to is this one in the init method:
Book(title: title, author: author, price: price, pubDate: pubDate)
But maybe that was how you were trying to assign the parameters. Either way, good luck!