Сергей Соколов

Как должен выглядеть json...

[
  {
    title: '...',
    children: [
      {
        title: '...',
        children: [
          {
            title: '...',
          },
          ...
        ],
      },
      ...
    ],
  },
  ...
]

...для генерации такого вложенного списка через v-for?

name: 'v-tree',
props: [ 'items' ],

<ul v-if="Array.isArray(items) && items.length">
  <li v-for="n in items">
    {{ n.title }}
    <v-tree :items="n.children" />
  </li>
</ul>

oldArray.sort((a, b) => a.id - b.id);
newArray.sort((a, b) => a.id - b.id);
oldIdx = 0;
newIdx = 0;
while (oldIdx < oldArray.length || newIdx < newArray.length) {
  if (oldIdx >= oldArray.length || oldArray[oldIdx].id > newArray[newIdx].id) {
    console.log(`Added id newArray[newIdx].id`);
    newIdx += 1;
    continue;
  }
  if (newIdx >= newArray.length || oldArray[oldIdx].id < newArray[newIdx].id) {
    console.log(`Deleted id oldArray[oldIdx].id`);
    oldIdx += 1;
    continue;
  }
  if (oldArray[oldIdx].x !== newArray[newIdx].x) {
    console.log(`Changed id newArray[newIdx].id`);
    oldIdx += 1;
    newIdx += 1;
  }
}

`${arr}`.match(/\b\w{5}\b/g) || []

// или

arr.reduce((acc, n) => (n.length ^ '0b101' || acc.push(n), acc), [])

// или

arr.filter(n => n[4] && !n[-~4])

// или

arr.filter(RegExp.prototype.test.bind(/^.....$/))

// или

arr.reduce((acc, n) => ((acc[n.search('$')] ??= []).push(n), acc), {})[5] ?? []

// или

(function get(i, n = arr[--i]) {
  return i >= 0
    ? get(i).concat(5 - [].push(...n) ? [] : n)
    : [];
})(arr.length)

function getNestedData(data, test) {
  const result = [];

  for (const stack = [ data ]; stack.length;) {
    const n = stack.pop();

    if (n instanceof Object) {
      stack.push(...Object.values(n).reverse());
    }

    if (test(n)) {
      result.push(n);
    }
  }

  return result;
}


console.log(getNestedData(tree, Number.isFinite));

async function() {
  let result = null;

  while (1) {
    result = await fetch(...);

    if (result тот, который нужен) {
      break;
    }

    await new Promise(r => setTimeout(r, 5000));
  }

  return result;
}

Array.from(document.querySelectorAll('.watch__price'), item => parseInt(item.textContent.match(/\d+/)));

// заменяем содержимое элемента main
main.innerHTML = arr.reduceRight(
  (content, tag) => `<${tag}>${content}</${tag}>`,
  ''
);

// или, дополняем его
main.insertAdjacentHTML(
  'beforeend',
  (function next(i, tag = arr[i] ?? '') {
    return tag && `<${tag}>${next(-~i)}</${tag}>`;
  })(0)
);

// замена контента
main.replaceChildren(...arr.reduceRight((content, tag) => {
  const el = document.createElement(tag);
  el.append(...content);
  return [ el ];
}, []));

// или, добавление
arr.reduce((el, tag) => (
  el.appendChild(document.createElement(tag)),
  el.lastChild
), main);

var arr = ['div', 'p', 'span'];
var main = document.querySelector('.main');

for (let i = 0, container = main; i < arr.length; i++) {
  let el = document.createElement(arr[i]);
  container.append(el);
  container = el;
}

const sorted = (data, key) => Array
  .from(data, n => [ key(n), n ])
  .sort(([a], [b]) => a < b ? -1 : +(a > b))
  .map(n => n[1]);

const sortChildren = (el, key) =>
  el.append(...sorted(el.children, key));

<button data-order="-1">От большего к меньшему</button>
<button data-order="+1">От меньшего к большему</button>

const wrapper = document.querySelector('.catalog-items');
const buttons = document.querySelectorAll('[data-order]');

buttons.forEach(n => n.addEventListener('click', onClick));

function onClick({ target: t }) {
  const order = +t.dataset.order;
  sortChildren(wrapper, el => parseInt(el.innerText) * order);
  buttons.forEach(n => n.classList.toggle('active', n === t));
}

Array.from(el.classList).forEach(n => el.classList.toggle(n, !!n.indexOf(classPrefix)));

el.classList.remove(...[...el.classList].filter(n => n.startsWith(classPrefix)));

for (let i = el.classList.length; i--;) {
  if (el.classList[i].search(classPrefix) === 0) {
    el.classList.remove(el.classList[i]);
  }
}

el.classList.value = el.classList.value
  .split(' ')
  .filter(RegExp.prototype.test.bind(RegExp(`^(?!${classPrefix})`)))
  .join(' ');

el.className = el.className.replace(RegExp(`(^| )${classPrefix}\\S*`, 'g'), '').trim();

const xxx = str => Array
  .from(str, (n, i) => n.toUpperCase() + n.toLowerCase().repeat(i))
  .join('-');

const xxx = str => str
  .toUpperCase()
  .split('')
  .reduce((acc, n, i) => `${acc}${i ? '-' : ''}${n}${Array(-~i).join(n.toLowerCase())}`, '');

const xxx = str => str
  .toUpperCase()
  .replace(/(?<=.)./g, (m, i) => '-'.concat(m, ...Array(i).fill(m.toLowerCase())));