CodexBloom - Programming Q&A Platform

scenarios Deserializing Nested JSON with Dynamic Keys in Go - Unrecognized Field

πŸ‘€ Views: 0 πŸ’¬ Answers: 1 πŸ“… Created: 2025-06-12
go json unmarshal Go

I've tried everything I can think of but I'm prototyping a solution and I'm relatively new to this, so bear with me. I'm working with an scenario while trying to deserialize a nested JSON structure in Go where the keys at a certain level are not known at compile time. The JSON payload looks like this: ```json { "user": { "id": 123, "name": "John Doe", "preferences": { "theme": "dark", "notifications": true, "customKey1": "value1", "customKey2": "value2" } } } ``` In my Go code, I have defined the struct as follows: ```go type User struct { ID int `json:"id"` Name string `json:"name"` Preferences map[string]interface{} `json:"preferences"` } ``` However, when I attempt to unmarshal the JSON into this struct using the following code: ```go var user User err := json.Unmarshal(jsonData, &user) if err != nil { log.Fatalf("behavior unmarshaling JSON: %v", err) } ``` I receive the behavior message `behavior unmarshaling JSON: json: unknown field 'customKey1'`. It seems like Go is having trouble recognizing the dynamic keys in the `preferences` map. I've confirmed that the JSON structure matches my struct definition exactly, yet it still throws this behavior. Looking into it, I tried to use `json.RawMessage` for the preferences field but that didn’t seem to help because I still need to access the dynamic keys later. What’s the best way to handle this situation in Go? Is there a best practice for dealing with nested JSON objects that have unpredictable keys? Any advice or examples would be greatly appreciated. For context: I'm using Go on Windows. What am I doing wrong? I'm working in a Windows 11 environment. What would be the recommended way to handle this?