⚡ Modern JavaScript Tips

// Array
const [first, second, ...rest] = [1, 2, 3, 4];

// Object
const { name, age = 25 } = user;

// Rename
const { name: userName } = user;

const city = user?.address?.city;    // undefined if missing
const name = user?.name ?? 'Guest';  // fallback value
const arr  = data?.items ?? [];      // safe array fallback

// map, filter, reduce
const doubled = nums.map(n => n * 2);
const evens   = nums.filter(n => n % 2 === 0);
const sum     = nums.reduce((acc, n) => acc + n, 0);

// flat & flatMap
const flat = [[1,2],[3,4]].flat();

// find & findIndex
const found = arr.find(x => x.id === 5);

async function fetchUser(id) {
  try {
    const res  = await fetch(`/api/users/${id}`);
    const data = await res.json();
    return data;
  } catch (err) {
    console.error('Fetch failed:', err);
  }
}

// Parallel requests
const [users, posts] = await Promise.all([fetchUsers(), fetchPosts()]);

// Remove duplicates
const unique = [...new Set(array)];

// Deep clone
const clone  = structuredClone(obj);

// Shuffle array
const shuffled = arr.sort(() => Math.random() - 0.5);

// Random int in range
const rand = Math.floor(Math.random() * (max - min + 1)) + min;

// Chunk array
const chunk = (arr, n) => Array.from({ length: Math.ceil(arr.length / n) }, (_, i) => arr.slice(i*n, i*n+n));