JSON

{
  "name": "রহিম",
  "age": 28,
  "isStudent": false,
  "courses": ["JS", "React"],
  "address": {
    "city": "ঢাকা",
    "zip": "1216"
  }
}

const text = '{"name":"রহিম","age":28}';

const obj = JSON.parse(text);
console.log(obj.name); // রহিম
console.log(obj.age);  // 28

const user = {
  name: "রহিম",
  age: 28,
  skills: ["JS", "React"],
};

const json = JSON.stringify(user);
console.log(json);
// {"name":"রহিম","age":28,"skills":["JS","React"]}

// সুসজ্জিত
console.log(JSON.stringify(user, null, 2));

const user = {
  name: "রহিম",
  age: 28,
  password: "secret123",
};

// password বাদ
const safe = JSON.stringify(user, ["name", "age"]);
console.log(safe); // {"name":"রহিম","age":28}

// অথবা function
const safe2 = JSON.stringify(user, (key, value) =>
  key === "password" ? undefined : value,
);
console.log(safe2);

async function saveUser() {
  const res = await fetch("/api/user", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ name: "রহিম", age: 28 }),
  });

  if (!res.ok) throw new Error(`HTTP ${res.status}`);
  const result = await res.json();   // উত্তর পড়া
  console.log(result);
}

const data = {
  users: [
    { id: 1, name: "রহিম", posts: [{ title: "অ্যারে" }] },
    { id: 2, name: "করিম", posts: [] },
  ],
};

const text = JSON.stringify(data);
const back = JSON.parse(text);

console.log(back.users[0].posts[0].title); // অ্যারে
console.log(back.users.length);             // 2

function safeParse(text) {
  try {
    return { ok: true, data: JSON.parse(text) };
  } catch (err) {
    return { ok: false, error: err.message };
  }
}

const good = safeParse('{"a":1}');
console.log(good.ok);   // true

const bad = safeParse("{a:1}");
console.log(bad.ok);    // false — Invalid JSON