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Why destructuring?

Destructuring lets you unpack values from objects and arrays into separate variables in a single line. Instead of writing user.name, user.email, user.role over and over, you extract them once. 
const user = { name: "Sarah", email: "sarah@example.com", role: "admin" };

// ❌ Without destructuring — repetitive
const name = user.name;
const email = user.email;
const role = user.role;

// ✅ With destructuring — one line
const { name, email, role } = user;

console.log(name);  // "Sarah"
console.log(email); // "sarah@example.com"
console.log(role);  // "admin"

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Object destructuring

Pull specific properties out of an object by name:
Python mental model: object destructuring is like doing multiple dict lookups and assignments in one step (name = user["name"], email = user["email"]) — but with a much shorter syntax.
const product = {
  id: 42,
  name: "Wireless Headphones",
  price: 79.99,
  category: "Electronics",
  inStock: true,
};

// Grab only what you need
const { name, price, inStock } = product;

console.log(name);    // "Wireless Headphones"
console.log(price);   // 79.99
console.log(inStock); // true
// id and category are ignored

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Renaming variables

When the property name conflicts with an existing variable or you want a clearer name: 
const apiResponse = { data: [...], error: null, status: 200 };

// Rename "data" to "users" and "status" to "httpStatus"
const { data: users, status: httpStatus } = apiResponse;

console.log(users);      // [...]
console.log(httpStatus);  // 200

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Default values

Set fallbacks for properties that might not exist: 
const settings = { theme: "dark" };

const { theme, language = "en", fontSize = 14 } = settings;

console.log(theme);    // "dark" (from the object)
console.log(language); // "en" (default — not in object)
console.log(fontSize); // 14 (default — not in object)
Python mental model: this is similar to settings.get("language", "en"). One key difference: destructuring defaults only apply when the property is undefined (missing). If the value is explicitly null, the default is not used.

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Nested destructuring

const order = {
  id: "ORD-001",
  customer: {
    name: "Sarah Chen",
    address: { city: "Portland", state: "OR" },
  },
};

const { customer: { name, address: { city } } } = order;

console.log(name); // "Sarah Chen"
console.log(city); // "Portland"
Don’t go more than two levels deep with nested destructuring. It quickly becomes unreadable. For deeply nested data, destructure in multiple steps or use dot notation.

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Array destructuring

Pull values out by position:
Python mental model: this is like tuple unpacking (first, second = values) — but JavaScript adds useful extras like skipping items and collecting “the rest” with ...remaining.
const colors = ["red", "green", "blue"];

const [first, second, third] = colors;

console.log(first);  // "red"
console.log(second); // "green"
console.log(third);  // "blue"

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Skipping items

const scores = [95, 87, 72, 91, 88];

// Skip the first two
const [, , third] = scores;
console.log(third); // 72

// Get first and rest
const [best, ...remaining] = scores;
console.log(best);      // 95
console.log(remaining);  // [87, 72, 91, 88]

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Swapping variables

let a = 1;
let b = 2;

[a, b] = [b, a];

console.log(a); // 2
console.log(b); // 1

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Where you’ll use destructuring every day

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React’s useState

You’ve already seen this — it’s array destructuring: 
const [count, setCount] = useState(0);
const [user, setUser] = useState(null);
const [isLoading, setIsLoading] = useState(false);
useState returns a two-element array: [currentValue, setterFunction]. Destructuring gives them meaningful names.

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React component props

// Without destructuring
function UserCard(props) {
  return <h2>{props.name}</h2>;
}

// With destructuring — cleaner
function UserCard({ name, email, role }) {
  return (
    <div>
      <h2>{name}</h2>
      <p>{email}</p>
      <span>{role}</span>
    </div>
  );
}

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Function parameters

// Extract what you need in the parameter list
function displayOrder({ id, customer, total }) {
  console.log(`Order ${id} for ${customer}: $${total}`);
}

displayOrder({ id: "ORD-001", customer: "Sarah", total: 149.99, items: [...] });
// "Order ORD-001 for Sarah: $149.99"
If you’re coming from Python, this feels like writing def display_order(order): ... and immediately doing id = order["id"], customer = order["customer"], total = order["total"] at the top of the function.

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API responses

async function getUser(userId) {
  const response = await fetch(`/api/users/${userId}`);
  const { name, email, role } = await response.json();
  return { name, email, role };
}

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Comparing to Python

// Object destructuring (no Python equivalent)
const { name, age } = user;

// Array destructuring
const [first, second] = [1, 2];

// In function params
function greet({ name, age }) {
  return `${name} is ${age}`;
}
Object destructuring is one of the biggest syntax wins JavaScript has over Python. It’s everywhere in React code.

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What’s next?

Destructuring unpacks values out of objects and arrays. The spread operator does the opposite — it expands them into new structures.

Spread operator

Copy, merge, and expand arrays and objects