JavaScript事件对象兼容性与事件委托机制详解

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <style>
    td{
      width: 100px;
      height: 100px;
      border:2px solid red;
    }
  </style>
</head>
<body>
<table >
  <tr>
    <td></td><td></td><td></td>
  </tr>
  <tr>
    <td></td><td></td><td></td>
  </tr>
  <tr>
    <td></td><td></td><td></td>
  </tr>
</table>
</body>
<script>
  var tab = document.getElementsByTagName("table")[0];
  tab.onclick = function (event) {
    //点击子级对象改变颜色
    event.target.style.backgroundColor = "black";
  }
</script>
</html>