PHP：随机加载3个html代码段之一

probably a simple thing but I can't think of an easy and good solution …

I want to load one of three videos randomly on page load …

  <video loop autoplay class="StretchtoFit">
    <source src="assets/videos/cloud.mp4" type="video/mp4">
    <source src="assets/videos/cloud.ogg" type="video/ogg">
    <source src="assets/videos/cloud.webm" type="video/webm">
  </video>
  <video loop autoplay class="StretchtoFit">
    <source src="assets/videos/bath.mp4" type="video/mp4">
    <source src="assets/videos/bath.ogg" type="video/ogg">
    <source src="assets/videos/bath.webm" type="video/webm">
  </video>
  <video loop autoplay class="StretchtoFit">
    <source src="assets/videos/train.mp4" type="video/mp4">
    <source src="assets/videos/train.ogg" type="video/ogg">
    <source src="assets/videos/train.webm" type="video/webm">
  </video>

The webpage is php-based. Is there any easy way to use a one of the three tags on random and don't load the other two?

How would you do that?

PHP:

$videos = array('cloud', 'bath', 'train');
$i = rand(0, count($videos) - 1); // between 0 and $videos count minus 1

HTML:

<video loop autoplay class="StretchtoFit">
 <source src="assets/videos/<?= $videos[$i]; ?>.mp4" type="video/mp4">
 <source src="assets/videos/<?= $videos[$i]; ?>.ogg" type="video/ogg">
 <source src="assets/videos/<?= $videos[$i]; ?>.webm" type="video/webm">
</video>

I'm using the short hand tag for echoing (<?php echo), <?=. Please make sure short_open_tag is enabled in your php.ini. Of course, you'll find out soon enough if it doesn't work.

<?php 
    $videos = ['cloud', 'bath', 'train'];
    $max    = count($videos);       // gives 3 
    $i      = rand(0, $max - 1);    // we need 0 to 2 
    $exts   = ['mp4','oog','webm']; // oog is not needed
?>

<video loop autoplay class="StretchtoFit">
<?php 
    foreach($exts as $ext):
        echo '<source src="assets/videos/'. $videos[$i].$ext. '" type="video/'. $ext .'">';
    endforeach; 
?>
</video>