sw213

const button = document.querySelector('.test');
const circle = document.querySelector('.circle');

button.addEventListener('click', () => {
  circle.style.transform = `translate(-50%, -50%) rotate(${circle.style.transform+30}deg)`;
});

const sortedData = useMemo(() => {
  return data
    .pages
    .flatMap(n => n.data)
    .sort((a, b) => b.liked.length - a.liked.length);
}, [ data ]);

<div className="App">
  {sortedData.map((item) => (
    <div>
    ...

const data = {
    pages: [{
        array1: [{
            id: 1,
            name: 'ivan'
        }, {
            id: 2,
            name: 'egor'
        }]
    }, {
        array2: [{
            id: 3,
            name: 'vlad'
        }, {
            id: 4,
            name: 'petr'
        }]
    }]
};

const id = 2;

function changeNameById(id, newName) {
    data.pages.forEach((page) => {
        Object.values(page).forEach((pageItem) => {
            const element = pageItem.find((item) => item.id === id);

            if (element) {
                element.name = newName;
            }
        });
    });
}

console.clear();

changeNameById(2, 'Valentin');
console.log(data);

{
  "pages": [
    {
      "array1": [
        {
          "id": 1,
          "name": "ivan"
        },
        {
          "id": 2,
          "name": "Valentin" // Изменённое имя
        }
      ]
    },
    {
      "array2": [
        {
          "id": 3,
          "name": "vlad"
        },
        {
          "id": 4,
          "name": "petr"
        }
      ]
    }
  ]
}

let a = 2;
let b = 2;
switch(true) {
  case a === b:
    console.log('=');
    break;
  case a > b:
    console.log('>');
    break;
  case a < b:
    console.log('<');
    break;
}

const mul = arr => arr.reduce((acc, n) => acc * n, 1);

// или

const mul = arr => eval(arr.join('*')) ?? 1;

// или

function mul(arr) {
  let result = 1;

  for (const n of arr) {
    result *= n;
  }

  return result;
}

// или

function mul(arr) {
  let result = 1;

  for (let i = 0; i < arr.length; i++) {
    result = result * arr[i];
  }

  return result;
}

// или

const mul = (arr, i = 0) => i < arr.length ? arr[i] * mul(arr, -~i) : 1;

const result = count.map(function(n) {
  return mul(data.slice(this[0], this[0] += n));
}, [ 0 ]);

const result = count.map(n => mul(data.splice(0, n)));