What are advanced Array methods?

const users = [
  { id: 1, name: 'John' },
  { id: 2, name: 'Jane' },
  { id: 3, name: 'Bob' }
];

// find - returns first match
const user = users.find(u => u.id === 2);
// { id: 2, name: 'Jane' }

// findIndex - returns index
const index = users.findIndex(u => u.id === 2);
// 1

// includes - check existence
[1, 2, 3].includes(2); // true

// indexOf - find index
[1, 2, 3].indexOf(2); // 1

const numbers = [1, 2, 3, 4, 5];

// some - at least one matches
numbers.some(n => n > 3);  // true
numbers.some(n => n > 10); // false

// every - all must match
numbers.every(n => n > 0); // true
numbers.every(n => n > 3); // false

// flat - flatten nested arrays
const nested = [1, [2, [3, [4]]]];
nested.flat();    // [1, 2, [3, [4]]]
nested.flat(2);   // [1, 2, 3, [4]]
nested.flat(Infinity); // [1, 2, 3, 4]

// flatMap - map then flatten
const sentences = ['Hello world', 'Hi there'];
sentences.flatMap(s => s.split(' '));
// ['Hello', 'world', 'Hi', 'there']

// fill
new Array(5).fill(0);  // [0, 0, 0, 0, 0]
[1, 2, 3].fill(0, 1);  // [1, 0, 0]

// Array.from
Array.from('hello');   // ['h', 'e', 'l', 'l', 'o']
Array.from({ length: 5 }, (_, i) => i);
// [0, 1, 2, 3, 4]

// Array.of
Array.of(1, 2, 3);     // [1, 2, 3]