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iOS Swift 2.0 Enumerations and Optionals Introduction to Optionals Nil Values in Collections

Posted by Matt Conway
Matt Conway
1,572 Points

if let statement

Not sure why this isn't 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.

/Users/mattconway/Desktop/Screen Shot 2016-03-09 at 8.10.45 PM.png

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

var leadActor: String = ""

// Enter code below

1 Answer

jcorum
jcorum
71,830 Points
jcorum
jcorum
71,830 Points

First you get the movie, then the cast, then the lead actor:

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

Optional chaining would usually be preferred, but the editor accepts this.