Handling incrementing JSON name using Swift

Question

I have a JSON object with incrementing names to parse and I want to store the output into an object with a name field and a list of pet field. I normally use JSONDecoder as

Answer 1

Codable has provisions for dynamic keys. If you absolutely can't change the structure of the JSON you're getting, you could implement a decoder for it like this:

struct VetShop: Decodable {
    let shopName: String
    let pets: [String]

    struct VetKeys: CodingKey {
        var stringValue: String
        var intValue: Int?
        init?(stringValue: String) {
            self.stringValue = stringValue
        }
        init?(intValue: Int) {
            self.stringValue = "\(intValue)";
            self.intValue = intValue
        }
    }

    init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: VetKeys.self)
        var pets = [String]()
        var shopName = ""
        for key in container.allKeys {
            let str = try container.decode(String.self, forKey: key)
            if key.stringValue.hasPrefix("pet") {
                pets.append(str)
            } else {
                shopName = str
            }
        }
        self.shopName = shopName
        self.pets = pets
    }
}