Swift 字典转字符串 与 字符串转字典

// MARK: 字典转字符串
   func dicValueString(_ dic:[String : Any]) -> String?{
        let data = try? JSONSerialization.data(withJSONObject: dic, options: [])
        let str = String(data: data!, encoding: String.Encoding.utf8)
        return str
    }

// MARK: 字符串转字典
   func stringValueDic(_ str: String) -> [String : Any]?{
        let data = str.data(using: String.Encoding.utf8)
        if let dict = try? JSONSerialization.jsonObject(with: data!, options: JSONSerialization.ReadingOptions.mutableContainers) as? [String : Any] {
            return dict
        }
        return nil
    }