JSON array inside of an array - ios

Question

I am looking to access a string that is located inside of a JSON array that is located inside of another array. I am accessing the JSON API using JSONDecoder. I am receiving errors when trying the various methods that I have used in the past when using JSON arrays.
Here is the code:
var country = [Results]()
struct Rating: Codable {
let results: [Results]
}
struct Results: Codable {
let iso_3166_1: String
let release_dates: [Release_Dates]
}
struct Release_Dates: Codable {
let certification: String
}
func loadRating() {
let id = filmId
let apiKey = ""
let url = URL(string: "https://api.themoviedb.org/3/movie/\(id)/release_dates?api_key=\(apiKey)")
let request = URLRequest(
url: url! as URL,
cachePolicy: URLRequest.CachePolicy.reloadIgnoringLocalCacheData,
timeoutInterval: 10 )
let session = URLSession (
configuration: URLSessionConfiguration.default,
delegate: nil,
delegateQueue: OperationQueue.main
)
let task = session.dataTask(with: request, completionHandler: { (dataOrNil, response, error) in
if let data = dataOrNil {
do { let rates = try! JSONDecoder().decode(Rating.self, from: data)
self.country = rates.results
let us = self.country.filter({ $0.iso_3166_1.contains("US") })
print(us)
}
}
})
task.resume()
}
us prints to console
[Film.DetailsView.Results(iso_3166_1: "US", release_dates: [Film.DetailsView.Release_Dates(certification: "PG-13")])]
I am trying to access the certification string.
What would be the correct method used to achieve this?

Answer 1

us is an array of Results.
To get the first certification use this:
print(us.first!.release_dates.first!. certification)
I am force unwrapping for brevity, you should properly do it with optional binding or the guard statement.

Answer 2

Pretty straightforward, the result of filter is an array and certification is in the array release_dates
let us = self.country.filter({ $0.iso_3166_1.contains("US") })
for item in us {
for releaseDate in item.release_dates {
print(releaseDate.certification)
}
}
Please name your struct member names lowerCamelCased by mapping the keys with CodingKeys or with the convertFromSnakeCase strategy.
If there is only one US item, use first
if let us = self.country.first({ $0.iso_3166_1.contains("US") }) {
for releaseDate in us.release_dates {
print(releaseDate.certification)
}
}