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

Ken Gerlinger
Ken Gerlinger
2,898 Points
Posted by Ken Gerlinger
Ken Gerlinger
2,898 Points

Hello am currently losing me mind on this challenge (array inside nested dictionary).

I would like to solve it on my own, but I need some advices. Could you explain to me how to access or call a String which is inside an array that it self is inside a nested dictionary? (e.g. - movieDictionary = [String: [String: [String]]] - )

Any other advices are appreciated!

cheers,

Ken

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

var leadActor: String = ""

// Enter code below

2 Answers

Heidi Puk Hermann
Heidi Puk Hermann
33,366 Points
Heidi Puk Hermann
Heidi Puk Hermann
33,366 Points

Hi,

you need to access each array/dictionary at a time, starting from the outside and going in. (Really hope this will make sense :) )

Imagine that you are building an app where people can store all their clothes. Each person has their own row, which contains a number of dictionaries - one for each type of clothes. The types of clothes are sorted by colour (just to have the same type of structure as you have...). 

var clothesDictionary = [
   "person1": ["shirts": ["blue", "black"], "pants": ["black", "white"]], 
   "person2": ["shirts": ["pink", "red"], "pants": ["cowboy", "black"]]
]

/* Access the colour of the second pair of pants for person2... 
    - Since I don't know if I have a person2, I have to check if he exists first.
    - Then check if he has any pants, and then I can get out the colors.*/

if let person = clothesDictionary["person2"], let pants = person["pants"] {
   var secondPantsColor: String = pants[1]
}

Hope that it can help you :)

Ken Gerlinger
Ken Gerlinger
2,898 Points
Ken Gerlinger
Ken Gerlinger
2,898 Points

Thank you so much !

Perfectly explained

Heidi Puk Hermann
Heidi Puk Hermann
33,366 Points
Heidi Puk Hermann
Heidi Puk Hermann
33,366 Points

Thank you for the feedback ! - It was a fun exercise for me to try and explain it, without giving away the answer, and I'm so happy it worked :D