1233211

const index = arr.findIndex(n => n.id === id);
if (index !== -1) {
  arr.splice(index, 1);
}

for (let i = arr.length; i--;) {
  if (arr[i].id === id) {
    arr.splice(i, 1);
  }
}

arr.reduceRight((_, n, i, a) => n.id === id && a.splice(i, 1), null);

let countDeleted = 0;

for (let i = 0; i < arr.length; i++) {
  arr[i - countDeleted] = arr[i];
  countDeleted += arr[i].id === id;
}

arr.length -= countDeleted;

arr.splice(0, arr.length, ...arr.filter(n => n.id !== id));

const getLast = (obj, parentName) =>
  obj.next instanceof Object
    ? getLast(obj.next, obj.name)
    : { ...obj, parentName };

numbers.filter(n => !objects.some(m => m.number === n))

numbers.filter(function(n) {
  return !this.has(n);
}, new Set(objects.map(n => n.number)))

numbers.filter(((nums, n) => !nums.includes(n)).bind(null, objects.map(n => n.number)))

Object.values(objects.reduce(
  (acc, n) => (delete acc[n.number], acc),
  numbers.reduce((acc, n) => (acc[n] = n, acc), {})
))

Array.from(objects.reduce(
  (acc, n) => (acc.delete(n.number), acc),
  new Map(numbers.map(n => [ n, n ]))
).values())

let arr2_plain = arr2.map(item => item.number);
let result = arr1.filter(item => !arr2_plain.includes(item));

const someObj = {
  title: 1,
  children: {
    title: 2,
    children: {
    	title: 3,
    }
  }
}

function getNestedObject(obj) {
	if (obj.children) {
  	return getNestedObject(obj.children)
  }
  
  return obj.title
}

console.log(getNestedObject(someObj)) // 3

const getLastChild = (obj) => obj.children ? getLastChild(obj.children) : obj;

let arr = "180820".split(/(\d\d)/).filter((_, i) => (i % 2)).reverse();
arr[0] = String(parseInt(arr[0]) + 2000);
console.log(new Date(arr.join("-")))

const url = new URL('http://mysite.com/page?users=all&page=2');
const params = new URLSearchParams(url.search);
const users = params.get('users');
console.log(users); // -> all

const data = await array.reduce(async (accumP, current, index) => {
  const accum = await accumP;
  …
}, Promise.resolve(…));

const wrapper = document.createElement('DIV') // создаем обертку
wrapper.className = 'myClass' // с классом

const target = document.querySelector('.root-content') // ищем целевой див

target.insertAdjacentElement('afterend', wrapper) // вставляем обертку сразу после цели
wrapper.appendChild(target) // перемещаем целевой внутрь обертки