This example builds on the JSON foundations from the previous page to show how real-world data — a list of people — is serialized into a nested JSON response. A helper function encapsulates the per-record construction, keeping main clean and readable.
// Serializar datos a JSON con std/json: json_object, json_array, json_stringify import "std/json" fn build_persona(nombre: String, edad: int, activo: bool) -> Array { let keys: Array = ["nombre", "edad", "activo"] let vals: Array = [] vals.push(json_string(nombre)) vals.push(json_number(edad)) vals.push(json_bool(activo)) return json_object(keys, vals) } fn main() -> int { // Objeto simple let persona: Array = build_persona("Bob", 25, true) print(json_stringify(persona)) // Array de objetos let lista: Array = [] lista.push(build_persona("Ana", 30, true)) lista.push(build_persona("Carlos", 40, false)) lista.push(build_persona("Dina", 22, true)) let arr: Array = json_array(lista) print(json_stringify(arr)) // Objeto anidado let meta_keys: Array = ["version", "total"] let meta_vals: Array = [] meta_vals.push(json_number(1)) meta_vals.push(json_number(3)) let meta: Array = json_object(meta_keys, meta_vals) let resp_keys: Array = ["meta", "data"] let resp_vals: Array = [] resp_vals.push(meta) resp_vals.push(arr) let resp: Array = json_object(resp_keys, resp_vals) print(json_stringify(resp)) return 0 }
{"nombre":"Bob","edad":25,"activo":true}
[{"nombre":"Ana","edad":30,"activo":true},{"nombre":"Carlos","edad":40,"activo":false},{"nombre":"Dina","edad":22,"activo":true}]
{"meta":{"version":1,"total":3},"data":[{"nombre":"Ana","edad":30,"activo":true},{"nombre":"Carlos","edad":40,"activo":false},{"nombre":"Dina","edad":22,"activo":true}]}How it works
build_persona is a plain Nyx function that takes typed arguments and returns a JSON object node. Wrapping construction logic in a function prevents key/value array mismatches and makes the code self-documenting — the function signature tells you exactly what fields each record contains.
Arrays of objects are built by pushing individual object nodes into a plain Array and wrapping the result with json_array. Because JSON nodes are just tagged arrays, they compose naturally: you can push an object node as the value of another object's field to create arbitrarily deep nesting.
The final resp object wraps meta and data into a single API-style response envelope. This pattern — a metadata object plus a data array — is common in REST APIs and shows how std/json handles real production shapes without any special-case syntax.