0xD34F

document.querySelector('form').addEventListener('click', ({ target: t }) => {
  let step = 0;
  if (t.classList.contains('btn-prev')) {
    step = -1;
  } else if (t.classList.contains('btn-next')) {
    step = 1;
  }

  if (step) {
    const select = t.closest('.section').querySelector('select');
    const optionsCount = select.options.length;
    select.selectedIndex = (select.selectedIndex + optionsCount + step) % optionsCount;
  }
});

let prevValue = input.value;
const VAL = определённое значение;

input.addEventListener('input', function() {
  if (this.value >= VAL && prevValue < VAL) {
    функция();
  }

  prevValue = this.value;
});

document.querySelector('.user-value-prompt').addEventListener('click', ({ target: t }) => {
  if (t.classList.contains('btn-value-transfer')) {
    t.closest('.user-value').querySelectorAll('.btn-value-transfer').forEach(n => {
      n.classList.toggle('btn-value-transfer-active', n === t);
    });
  }
});

(entities[currentBrand] ?? []).map(n => (
  <ListItem>
    {n.icon}
    {n.label}
  </ListItem>
))

const selectors = [ '.addservice', '.addprice' ];
const data = Array.from(
  document.querySelectorAll('.addserviceBlock'),
  n => selectors.map(m => n.querySelector(m).value)
);

menuEl.innerHTML = Array
  .from(
    document.querySelectorAll('section > h2'),
    n => `<a href="#${n.parentNode.id}">${n.innerText}</a>`)
  .join('');

Object.entries(test).find(n => n[1].includes(val))?.[0]

function chunked(str, chunkCount) {
  const chunkLen = Math.ceil(str.length / chunkCount);
  return Array.from(
    { length: chunkCount },
    (n, i) => str.slice(i * chunkLen, (i + 1) * chunkLen)
  );
}

function chunked(str, chunkCount) {
  return str.match(RegExp(`.{1,${Math.ceil(str.length / chunkCount)}}`, 'g'));
}

function chunked(str, chunkCount) {
  return str.split(RegExp(`(.{${Math.ceil(str.length / chunkCount)}})`)).filter(Boolean);
}

неаккуратненько как-то:
chunked('test', 3) // [ "te", "st", "" ]

const chunked = (str, chunkCount) =>
  chunkCount <= str.length
    ? Array.from(
        { length: chunkCount },
        function(n, i) {
          return str.slice(i * this, i === chunkCount - 1 ? str.length : (i + 1) * this);
        },
        str.length / chunkCount | 0
      )
    : 'извини, столько непустых кусков нарезать нельзя';

const sectionAttribute = element.getAttribute('data-content')

const titles = document.querySelectorAll('[data-title]');
const contents = document.querySelectorAll('[data-content]');

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

function onClick({ target: t }) {
  titles.forEach(n => n.classList.toggle('active', n === t));
  contents.forEach(n => n.hidden = n.dataset.content !== t.dataset.title);
}

Object.values(arr.reduce((acc, { name, ...n }) => (
  Object.values(n).pop().forEach(({ scores, channel }) =>
    scores.forEach(({ score }) =>
      (acc[channel]?.score > score) || (acc[channel] = { channel, name, score })
    )
  ),
  acc
), {}))

const toggleSearchParams = params => {
  const newSearchParams = [...searchParams];

  for (const n of params) {
    const index = newSearchParams.findIndex(m => n[0] === m[0] && n[1] === m[1]);
    if (index === -1) {
      newSearchParams.push(n);
    } else {
      newSearchParams.splice(index, 1);
    }
  }

  setSearchParams(newSearchParams);
};

const handleChangeCheckBoxValue = e => {
  toggleSearchParams([ [ 'selected', e.target.value ] ]);
};

const handleDeleteParams = () => {
  toggleSearchParams(checkboxParams.map(n => [ 'selected', n ]));
};