Swift 4 JSON Decodable simplest way to decode type change

Question

With Swift 4\'s Codable protocol there\'s a great level of under the hood date and data conversion strategies.

Given the JSON:

{
    \"name\": \"Bob\         


        

Answer 1

I used Suran's version, but updated it to return non-optional value for decode(). To me this is the most elegant version. Swift 5.2.

extension KeyedDecodingContainer {

func decodeIfPresent(_ type: Float.Type, forKey key: K, transformFrom: String.Type) throws -> Float? {
    guard let value = try decodeIfPresent(transformFrom, forKey: key) else {
        return nil
    }
    return Float(value)
}

func decode(_ type: Float.Type, forKey key: K, transformFrom: String.Type) throws -> Float {
    guard let str = try? decode(transformFrom, forKey: key),
        let value = Float(str) else {
            throw DecodingError.typeMismatch(Int.self, DecodingError.Context(codingPath: codingPath, debugDescription: "Decoding of \(type) from \(transformFrom) failed"))
    }
    return value
}
}