Play video on hover only working on the first element

When the mouse hovers over a div a video will play. Everything works fine but the video only plays on the first “player”. I can see the thumbnail on every player but they don’t start to play. Why is this happening?

<?php
    foreach($posts as $post)
    {
      $vimeoid = get_field('film_vimeo', $post, true);
      if (empty($vimeoid)) 
      {
        $projektclass = "not-vimeo";
      }
      else 
      {
        $projektclass = "vimeo";
      } 

      //echo '<div id="hp-post"><a href="' . get_permalink($post->ID) . '">' . get_the_title($post->ID) . '</a></div>';
      echo '<div class="'.$projektclass.'" style="position: relative;" id="hp-post">';
      echo get_the_post_thumbnail( $post, 'full' );
      echo '<div id="'.$vimeoid.'"><iframe class="vimeoplayer" id="'.$vimeoid.'" style="position: absolute; z-index:-1;" src="https://player.vimeo.com/video/'.$vimeoid.'?title=0&byline=0&portrait=0&background=1&autoplay=0 width="100%" height="0" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe></div></div>';
    }
    echo '</div>';
  }
?>

jQuery(document).ready(function() {
  var vimeo = document.getElementsByClassName('vimeo')[0];
  var player = new Vimeo.Player(vimeo);

  vimeo.onmouseover = function() {
    return player.play();
  };
  
  vimeo.onmouseout = function() {
    return player.pause();
  };
});

Answer

The issue is because you only retrieve the first item in the collection of elements (ie. the [0] item) and bind events to that. None of the other elements are affected. To fix this you need to loop through them.

I would also suggest using addEventListener() for this instead of the onX event properties. Try this:

jQuery($ => {
  Array.from(document.getElementsByClassName('vimeo')).forEach(el => {
    let player = new Vimeo.Player(el);
    el.addEventListener('mouseover', () => player.play());
    el.addEventListener('mouseout', () => player.pause());
  });
});