0xD34F

указываю inheritAttrs: false <...> классы все равно прописваются в корневой элемент

this option does not affect class and style bindings

state: {
  user:{
    name:'',

updateName(state, name){
  state.name=name;

user() {
  return new Proxy(this.$store.state.user, {
    set: (target, prop, value) => {
      this.$store.commit('updateUser', { [prop]: value });
      return true;
    },
  });
},

updateUser(state, user) {
  Object.assign(state.user, user);
},

<input v-model="user.name">
<input v-model="user.surname">
<input v-model="user.email">
<input v-model="user.phone">

const u = users.find(n => n.id === id);
if (u) {
  Object.assign(u, user);
} else {
  // добавляем, например
  users.push({ ...user, id });
}

const ScrollButton = props => {
  const onClick = () => window.scrollTo({
    top: props.scrollTo,
    behavior: 'smooth',
  });

  return (
    <div className="down" style={{ top: `${props.top}px` }}>
      Scroll to {props.scrollTo}
      <button onClick={onClick}>&#10095;</button>
    </div>
  );
};

const App = () => (
  <div className="container">
    <ScrollButton scrollTo={500} top={50} />
    <ScrollButton scrollTo={1000} top={100} />
    <ScrollButton scrollTo={2000} top={200} />
  </div>
);

.down {
  position: fixed;
}

const usersList = users.map(n => `${n.firstName} ${n.lastName} ${n.email}`);

const usersList = users.map(function(n) {
  return this.map(k => n[k]).join(' ');
}, [ 'firstName', 'lastName', 'email' ]);

methods: {
  onKeyDown(e) {
    ...
  },
  ...
},
created() {
  document.addEventListener('keydown', this.onKeyDown);
},

onInput({ target }) {
  const
    val = target.value,
    newVal = `${Math.min(9, Math.max(0, val.slice(-1) | 0))}`;

  if (val !== newVal) {
    target.value = newVal;
    target.dispatchEvent(new Event('input'));
  }
},

const containerSelector = '.container';
const buttonSelector = 'button';
const activeContainerClass = 'btn-active';
const activeButtonClass = 'active';

$(document).on('click', buttonSelector, function(e) {
  const $button = $(this).toggleClass(activeButtonClass);
  $button
    .closest(containerSelector)
    .toggleClass(activeContainerClass, $button.hasClass(activeButtonClass))
    .find(buttonSelector)
    .not($button)
    .removeClass(activeButtonClass);
});

document.addEventListener('click', e => {
  const button = e.target.closest(buttonSelector);
  if (button) {
    const container = button.closest(containerSelector);
    container.querySelectorAll(buttonSelector).forEach(n => {
      n.classList[n === button ? 'toggle' : 'remove'](activeButtonClass);
    });
    container.classList.toggle(
      activeContainerClass,
      button.classList.contains(activeButtonClass)
    );
  }
});

$('#btn__AddEmployee').click(function() {
  const checked = $(this).prev().prop('checked');

  $('#table__Employee tbody').append(`
    <tr>
      <td>
        <input type="checkbox" ${checked ? 'checked="checked"' : ''}>
      </td>
    </tr>
  `);
});

document.querySelector('#btn__AddEmployee').addEventListener('click', e => {
  const input = document.createElement('input');
  input.type = 'checkbox';
  input.checked = e.target.previousElementSibling.checked;

  document
    .querySelector('#table__Employee tbody')
    .insertRow()
    .insertCell()
    .append(input);
});

const count = matrix.flat().reduce((acc, n) => (acc[n] = -~acc[n], acc), {});

const count = {};

for (const row of matrix) {
  for (const n of row) {
    if (!count.hasOwnProperty(n)) {
      count[n] = 0;
    }

    count[n]++;
  }
}

Где ошибся?

document.querySelector('.selectTime').addEventListener('change', function() {
  const values = Array.from(this.querySelectorAll('select'), n => n.value);
  values[0] = `${-~values[0] % 24}`;

  document.querySelector('куда там вам надо записать время').innerText = values
    .map(n => n.padStart(2, 0))
    .join(':');
});