Сергей Соколов

const half = [0, 150]; // [ первый кадр, средний кадр ]

if (this.showMobileMenu === true) {
    burgerLottieIcon.setDirection(1);
    burgerLottieIcon.playSegments(half, true);
} else {
    burgerLottieIcon.setDirection(-1);
    burgerLottieIcon.playSegments(half, true);
}

function getByChance(items) {
  const totalChances = items.reduce((acc, c) => acc + c.dropChance, 0);
  const rnd = totalChances * Math.random();

  for (let i = 0, sum = 0;; i++) {
    sum += items[i].dropChance;
    if (sum > rnd) return items[i];
  }
}

getByChance(items) // вернёт один из объектов массива

'style="background-image: url(\'' + elem['meta']['feedback_user_feedback_user_photo'] + '\')"></div>';

response.data.post.forEach(function(elem) {
  content += `
    <div class="full-reviews__slide expand-review">
      <div class="row mb-4">
        <div class="expand-review__author-info col-12 col-lg-4 col-xl-3">
          <div
            class="expand-review__author-thumb"
            style="background-image: url('${elem['meta']['feedback_user_feedback_user_photo']}')">
          </div>
        </div>
        <div class="expand-review__content col-12 col-lg-8 col-xl-9">
          <h2 class="expand-review__title">${elem['meta']['feedback_title']}</h2>
          <p class="expand-review__excerpt">
            ${elem['meta']['feedback_shortdesc']}
          </p>
          <a href="${elem['meta']['permalink']}" class="expand-review__read-more">Читать полностью</a>
        </div>
      </div>
    </div>
  `;

function changeHeight(selector) {
  const height = parseInt(selector.style.height);
  const percentage = 94 - 2 * Math.floor((height - 42) / 16);
  chats.style.height = percentage + "%";
}

const liveList = document.getElementsByClassName('my-class');
let maxAttempts = 5;
const getPopup = () => {
  if (liveList.length > 0) {
    console.log(liveList[0].textContent);
  } else if (maxAttempts-- > 0) {
    setTimeout(getPopup, 500);
  }
};

getPopup();

document.getElementById("tot-id") && document.querySelector("footer > div").classList.add("tot-class");

if (document.getElementById("tot-id")) {
  document.querySelector("footer > div")
    .classList
    .add("tot-class");
}

let resultArr = products.filter((product) => {
  return product.price > 100;
});

// или
let resultArr = products.filter((product) => product.price > 100);

array.map(({id}) => id) // [ "a", "b", "c", "c" ]
  .forEach((id, _, arr) => {
    if (arr.indexOf(id) !== arr.lastIndexOf(id)) {
      console.log(id);
    }
  })

Object.defineProperty(window, "test", {
  value: "QnA"
});

test = "X"; 
test // "QnA"

var test = "Y";
test // "QnA"

window.test = "Habr";
test // "QnA"

const test = "Z" // Uncaught SyntaxError: redeclaration of var test

var test = "Habr";

Object.defineProperty(window, "test", {
  value: "QnA",
  writable: false,
});

1. один погасить через пол-секунды транзишн,
   
2. второй назначить следующий слайд