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iOS Enumerations and Optionals in Swift Introduction to Optionals Nil Values in Collections

Posted by isaacrichardson
isaacrichardson
14,313 Points

I'm not sure why it is not working

In the editor, you have a pretty complex dictionary representing a movie. It contains a nested dictionary, which itself contains an array of Strings as a value.

Your job is to assign the string containing the value for the lead actor (which for the sake of the example is at position 0 in the array) to the variable leadActor.

Since dictionaries return optional values, you will have to use an if let statement to unwrap each consecutive operation.

What I'm I doing wrong hear

optionals.swift 
let movieDictionary = ["Spectre": ["cast": ["Daniel CraThe ig", "Christoph Waltz", "LÊa Seydoux", "Ralph Fiennes", "Monica Bellucci", "Naomie Harris"]]]

var leadActor: String = ""

// Enter code below

if let movie = movieDictionary["Spectre"], let cast = movie["cast"], let lead = cast[0] {
  leadActor = lead
}

1 Answer

Paul Brazell
Paul Brazell
14,371 Points
Paul Brazell
Paul Brazell
14,371 Points

2 things of note here.

First, I think you may have accidentally modified the movie dictionary value for "Daniel Craig". You may want to fix that first.

Secondly, I would suggest copying the code any pasting it into a playground in Xcode. I think the compiler error in there will lead to the answer you are looking for.

Hint: What does an if let statement unwrap?