Использовать JSONDecoder().decode
См. это видео Разбор JSON с Swift 4
struct Post: Codable {
let userId: Int
let id: Int
let title: String
let body: String
}
URLSession.shared.dataTask(with: URL(string: "https://jsonplaceholder.typicode.com/posts")!) { (data, response, error) in
guard let response = response as? HTTPURLResponse else {
print("HTTPURLResponse error")
return
}
guard 200 ... 299 ~= response.statusCode else {
print("Status Code error \(response.statusCode)")
return
}
guard let data = data else {
print("No Data")
return
}
let posts = try! JSONDecoder().decode([Post].self, from: data)
print(posts)
}.resume()