CSSテーブルの空セル属性の詳細な分析

table {
  empty-cells: hide;}

<table cellspacing="0" id="table">
  <tr>
    <th>Fruits</th>
    <th>Vegetables</th>
    <th>Rocks</th>
  </tr>
  <tr>
    <td></td>
    <td>Celery</td>
    <td>Granite</td>
  </tr>
  <tr>
    <td>Orange</td>
    <td></td>
    <td>Flint</td>
  </tr></table>
  <button id="b" data-ec="hide">切换EMPTY-CELLS</button>

body {
  text-align: center;
  padding-top: 20px;
  font-family: Arial, sans-serif;}table {
  border: solid 1px black;
  border-collapse: separate;
  border-spacing: 5px;
  width: 500px;
  margin: 0 auto;
  empty-cells: hide;
  background: lightblue;}th, td {
  text-align: center;
  border: solid 1px black;
  padding: 10px;}button {
  margin-top: 20px;}

var b = document.getElementById('b'),
    t = document.getElementById('table');b.onclick = function () {
  if (this.getAttribute('data-ec') === 'hide') {
    t.style.emptyCells = 'show';
    this.setAttribute('data-ec', 'show');
  } else {
    t.style.emptyCells = 'hide';
    this.setAttribute('data-ec', 'hide');
  }};