Nested JSON Objects to Nested Go Structs

Handling Nested JSON Objects in Go

Real-world JSON almost always contains nested objects. In Go, each nested object becomes its own struct type, and the parent struct holds a field of that type.

Example JSON

{
  "user": {
    "name": "Bob",
    "age": 30,
    "address": {
      "street": "123 Main St",
      "city": "Springfield",
      "zip": "62704"
    }
  }
}

Generated Go Structs

type AutoGenerated struct {
    User User `json:"user"`
}

type User struct {
    Name    string  `json:"name"`
    Age     int     `json:"age"`
    Address Address `json:"address"`
}

type Address struct {
    Street string `json:"street"`
    City   string `json:"city"`
    Zip    string `json:"zip"`
}

How Nesting Works

Go does not support anonymous inline object types like TypeScript does. Every nested JSON object requires a named struct type. The converter generates a separate struct for each level of nesting and names it based on the parent key.

Naming Conventions

When the JSON key is "address", the struct type becomes Address. If there are naming collisions (two different objects both called "data"), the converter typically appends the parent name to disambiguate, producing types like UserData and OrderData.

Unmarshaling Nested Data

var response AutoGenerated
json.Unmarshal([]byte(jsonData), &response)
fmt.Println(response.User.Address.City) // "Springfield"

Go's encoding/json package recursively processes each nested object, matching JSON keys to struct tags at every level. This makes deeply nested structures fully navigable with standard dot notation.