Playground:
import UIKit
let people = [ [
"name" : "Bob",
"Age" : 35,
"cars" : [
["type" : "Mercedes GL",
"occupancy" : 7,
"mpg" : 21],
["type" : "Mazda",
"occupancy" : 2,
"mpg" : 24] ]
],[
"name" : "Billy",
"Age" : 26,
"cars" : [
["type" : "VW Golf",
"occupancy" : 5,
"mpg" : 30] ]
]
]
print(people[0]["name"]!)
print(people[0]["cars"]![0]["occupancy"])
The was print function gives me Bob's name. However I am struggling to get the occupancy of his Mercedes car. The second print command gives me "Type 'Any' has no subscript members" as an error. How can I extract the data from the above structure?
Many thanks
Swift doesn't have a direct natural way of handling heterogenous tree structures built out of collections. The (inferred) type of the "people" variable is [[String: Any]] (an array of dictionaries with strings as keys). That's why you get your error message. To solve it in this case, you should be able to do something like:
(people[0]["cars"] as! [[String: Any]]) [0]["occupancy"]This involves a runtime check for the type of the "cars" member.
A better way to do this is to declare explicit types for Person and Car, and build your data out of those types.
