Parsing Nested JSON with Variable Depth in Swift - Unexpected Nil Values
I've been banging my head against this for hours. I'm working on a Swift application that requires parsing a nested JSON response from an API that has variable depth. The structure can vary significantly based on the data available. For example, one response might contain properties as follows: ```json { "user": { "id": 1, "name": "John Doe", "address": { "street": "123 Main St", "city": "Anytown", "state": "CA" } } } ``` But another response might include additional nested properties: ```json { "user": { "id": 2, "name": "Jane Smith", "address": { "street": "456 Elm St", "city": "Othertown", "state": "NY", "zip": "12345" } } } ``` I am using `Codable` to parse this JSON, but I'm running into issues when certain fields are missing in the response. For example, if the `zip` field is not included in the response, the parsing seems to unexpected result and I get `nil` values in my model when I try to access them. Here’s the code I have so far: ```swift struct User: Codable { let id: Int let name: String let address: Address } struct Address: Codable { let street: String let city: String let state: String let zip: String? // Optional to handle missing zip } let jsonData = /* Data from the API */ do { let user = try JSONDecoder().decode(User.self, from: jsonData) print(user) } catch { print("Failed to decode JSON: \(behavior)") } ``` I’ve tried marking optional fields, like `zip`, but I still find that when the key doesn't exist, it leads to my model being incomplete, and I get unexpected results when I try to access these properties. For instance, accessing `user.address.zip` when it's missing returns `nil`, but I’m not sure how to handle the absence of keys more gracefully. Is there a way to ensure that my model remains intact even when certain keys are missing? Should I be using `try?` or implementing custom decoding logic to manage this? Any advice would be appreciated! My development environment is Ubuntu 22.04. Any examples would be super helpful.