Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

iOS Enumerations and Optionals in Swift Introduction to Optionals Initializing Optional Values

Posted by eliotanke
eliotanke
2,542 Points

My code compiles in Xcode but doesn't compile in the editor. What discrepancies do the two editors have?

I do not get any compilation errors. Only a message that says that compilation has failed and that I should click preview for details. However, clicking preview displays a blank page. Please see my code for details.

optionals.swift 
struct Book {
  let title: String
  let author: String
  let price: String?
  let pubDate: String?

  init?(dictionary: [String: String]) {
    guard let dictTitle = dictionary["title"], let dictAuthor = dictionary["author"] else {
      return nil
    }
    price = dictionary["price"]
    pubDate = dictionary["pubDate"]
    title = dictTitle
    author = dictAuthor
  }
}

1 Answer

David Papandrew
David Papandrew
8,386 Points
David Papandrew
David Papandrew
8,386 Points

The challenge wants the dictionary argument to be named "dict". Make this change and the code should pass.

struct Book {
    let title: String
    let author: String
    let price: String?
    let pubDate: String?

    init?(dict: [String: String]) {
        guard let dictTitle = dict["title"], let dictAuthor = dict["author"] else {
            return nil
        }

        self.title = dictTitle
        self.author = dictAuthor
        self.price = dict["price"]
        self.pubDate = dict["pubDate"]
    }
}