x
 
<!DOCTYPE html> 
<html> 
<body> 
<video id="myVideo" width="640" height="360" controls loop>
  <source src="/i/video/shanghai.mp4" type="video/mp4">
  <source src="/i/video/shanghai.ogg" type="video/ogg">
  您的浏览器不支持 video 标签。
</video>
<p>单击按钮可了解视频是否应在每次播放结束后重新开始播放。</p>
<button onclick="myFunction()">试一试</button>
<p id="demo"></p>
<script>
function myFunction() {
  var x = document.getElementById("myVideo").loop;
  document.getElementById("demo").innerHTML = x;
}
</script>
</body> 
</html>