Сергей Соколов

document.getElementById('collapsible').addEventListener('click', () => document.getElementById('portfolio').classList.toggle('active'))

const [ first, ...rest ] = document.querySelectorAll('[type="checkbox"]');
const onChange = () => first.checked = rest.every(n => n.checked);
first.addEventListener('change', () => rest.forEach(n => n.checked = first.checked));
rest.forEach(n => n.addEventListener('change', onChange));

return arr.reduce((acc, rec, index) => {
    return (typeof acc[rec] !== 'undefined')
      ? { ...acc, [rec]: acc[rec] + 1 }
      : { ...acc, [rec]: 1 }
  }, {});

var downloadButton = document.getElementById("download");
var counter = 10;
var newElement = document.createElement("div");
newElement.innerHTML = "You can download the file in 10 seconds.";
var id;

newElement.classList.add('Class');

downloadButton.parentNode.replaceChild(newElement, downloadButton);

id = setInterval(function() {
    counter--;
    if(counter < 0) {
        newElement.parentNode.replaceChild(downloadButton, newElement);
        clearInterval(id);
    } else {
        newElement.innerHTML = "You can download the file in " + counter.toString() + " seconds.";
    }
},  1000);

string.split(' ')
  .sort((a, b) => parseInt(a.match(/\d+/)) - parseInt(b.match(/\d+/)))
  .join(' ');

const keyIndex = arr.reduce((acc, n, i) => (acc[n.key] ??= i, acc), {});

arr.sort((a, b) => (keyIndex[a.key] - keyIndex[b.key]) || (a.id - b.id));

const sorted = (arr, keys) => arr
  .map(n => [ n ].concat(keys(n)))
  .sort((a, b) => {
    let diff = 0;
    for (let i = 0; ++i < a.length && !(diff = a[i] - b[i]);) ;
    return diff;
  })
  .map(n => n[0]);


const sortedArr = sorted(arr, n => [ keyIndex[n.key], n.id ]);

const reverse = number => +[...`${Math.abs(number)}`].reverse().join('');

function getWinner(points) {
  const [ a, b ] = points.reduce((acc, n) => (
    n.split('-').forEach((m, i) => acc[i] += +m),
    acc
  ), [ 0, 0 ]);

  return a === b
    ? undefined
    : a < b ? 2 : 1;
}

const getWinner = points => [ 2, , 1 ][Math.sign(eval(points.join('+'))) + 1];