Exemples JSON en 7 langages : JavaScript, Python, Go, Rust, PHP, Java, C#

// Parse a JSON string into an object (always guard with try/catch)
let data;
try {
  data = JSON.parse('{"name": "Alice", "age": 30}');
  console.log(data.name); // "Alice"
} catch (err) {
  console.error("Invalid JSON:", err.message);
}

// Serialize an object back to JSON
const json = JSON.stringify(data, null, 2);

// Fetch JSON from an API (res.json() rejects on invalid JSON)
const res = await fetch("/api/users/1");
const user = await res.json(); // parsed automatically

import json

# Parse JSON string into a dict
data = json.loads('{"name": "Alice", "age": 30}')

# Serialize a dict to a pretty JSON string
text = json.dumps(data, indent=2, ensure_ascii=False)

# Read/write a JSON file
with open("data.json", encoding="utf-8") as f:
    data = json.load(f)

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

// Struct → JSON
b, _ := json.Marshal(User{Name: "Alice", Age: 30})

// JSON → struct
var u User
_ = json.Unmarshal([]byte(`{"name":"Bob","age":25}`), &u)

use serde::{Deserialize, Serialize};

#[derive(Serialize, Deserialize)]
struct User {
    name: String,
    age: u8,
}

fn main() -> Result<(), serde_json::Error> {
    // JSON → struct
    let u: User = serde_json::from_str(r#"{"name":"Alice","age":30}"#)?;

    // Struct → JSON (pretty-printed)
    let json = serde_json::to_string_pretty(&u)?;
    println!("{}", json);
    Ok(())
}

<?php
// PHP array → JSON
$json = json_encode(["name" => "Alice", "age" => 30],
    JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);

// JSON → PHP array
$data = json_decode($json, true);
if (json_last_error() !== JSON_ERROR_NONE) {
    echo "JSON error: " . json_last_error_msg();
}

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.DeserializationFeature;

record User(String name, int age) {}

ObjectMapper mapper = new ObjectMapper()
    .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

// JSON → record
User user = mapper.readValue("{\"name\":\"Alice\",\"age\":30}", User.class);

// Record → JSON
String json = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(user);

using System.Text.Json;
using System.Text.Json.Serialization;

public class User
{
    [JsonPropertyName("name")]
    public string Name { get; set; } = "";

    [JsonPropertyName("age")]
    public int Age { get; set; }
}

// JSON → object
var user = JsonSerializer.Deserialize<User>(
    "{\"name\":\"Alice\",\"age\":30}")!;

// Object → JSON (camelCase to match JSON conventions)
var options = new JsonSerializerOptions {
    PropertyNamingPolicy = JsonNamingPolicy.CamelCase
};
string json = JsonSerializer.Serialize(user, options);