Swift 字典数组转Json字符串 换行符处理

方法一：

    class func jsonArray(res: [Any]) -> String {
        if (!JSONSerialization.isValidJSONObject(res)) {
            print("无法解析出JSONString")
            return " "
        }
        if let data = try? JSONSerialization.data(withJSONObject: res, options: [.fragmentsAllowed,.prettyPrinted]), let JSONString = NSString(data:data as Data,encoding: String.Encoding.utf8.rawValue) as String? {
            return JSONString
        }
        return " "
    }

注意：如果options里面有值的话，转换的json字符串里面会带有换行符
如果需要去掉换行符，只需要把options参数设置为空即可

方法二：

    class func getJSONStringFromArray(array: [Any]) -> String {
        if (!JSONSerialization.isValidJSONObject(array)) {
            print("无法解析出JSONString")
            return " "
        }
        if let data = try? JSONSerialization.data(withJSONObject: array, options: []), let JSONString = NSString(data:data as Data,encoding: String.Encoding.utf8.rawValue) as String? {
            return JSONString
        }
        return " "
    }