Need help with Optionals Challenge

Hi,

ok this one is tricky.

As you know it is safe to extract optional using if let, like: let title = dict["title"]

extracted value if set properly in dictionary should give us desired string. But as you may know dictionary may not have value for key "title", so what it does it gives you optional by default. And when you extract it, it will either have your value or nil.

But in our case we have only two properties of struct Book being optionl, and other two being just regular string. So we assume that it is ok if price and pubDate will have nil, and actually, we don't even need to extract it. Because we declared them in our struct as optionals, means we can live with there value set to nil or string and wrapped in optional.

I know it can be little messy, but what you need to focus on is to use if let to extract optionals, use self for class properties to set them correctly and finally assign unwrapped optional string to regular string and leve default dictionary optionals as they can do no harm.

Please refer to code below:

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
      }
    }
}

Good luck!

Cheers!