TryIt Editor v2.0 - Javascript scrolls into view

Source Code: (back to article)

<!DOCTYPE html>
<html>
  <head>
    <title>Title of the document</title>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.0/jquery.min.js"></script>
    <style>
      .largebox {
        height: 1500px;
      }
      .box {
        height: 400px;
      }
    </style>
  </head>
  <body>
    <div class="largebox">
      <div id="msg" style="position:fixed;left:30%;"></div>
      <div class="box">First box</div>
      <div id="box1" class="box1">Second box</div>
    </div>
    <script>
      function isVisible($el) {
        let docViewTop = $(window).scrollTop();
        let docViewBottom = docViewTop + $(window).height();
        let elTop = $el.offset().top;
        let elBottom = elTop + $el.height();
        return((elBottom <= docViewBottom) && (elTop >= docViewTop));
      }
      $(function() {
        $("#msg").text("#Second box  visible=" + isVisible($("#box1")));
        $(window).scroll(function() {
            $("#msg").text("Second box visible=" + isVisible($("#box1")));
          });
      });
    </script>
  </body>
</html>