OnScroll Hide Menu

Onscroll hide menu bar

by Suryar Praveen

HTML

<div id="navbar">
  <a href="#home">Home</a>
  <a href="#news">News</a>
  <a href="#contact">Contact</a>
</div>
<div style="padding:15px 15px 2500px;font-size:30px;margin-top:30px;">
  <p><b>This example demonstrates how to hide a navbar when the user starts to scroll the page.</b></p>
  <p>Scroll down this frame to see the effect!</p>
  <p>Scroll up to show the navbar.</p>
  </div>

CSS

body {
  margin: 0;
  background-color: #f1f1f1;
  font-family: Arial, Helvetica, sans-serif;
}

#navbar {
  background-color: #333;
  position: fixed;
  top: 0;
  width: 100%;
  display: block;
  transition: top 0.3s;
}

#navbar a {
  float: left;
  display: block;
  color: #f2f2f2;
  text-align: center;
  padding: 15px;
  text-decoration: none;
  font-size: 17px;
}

#navbar a:hover {
  background-color: #ddd;
  color: black;
}

JavaScript

var prevScrollpos = window.pageYOffset;
window.onscroll = function() {
var currentScrollPos = window.pageYOffset;
  if (prevScrollpos > currentScrollPos) {
    document.getElementById("navbar").style.top = "0";
  } else {
    document.getElementById("navbar").style.top = "-50px";
  }
  prevScrollpos = currentScrollPos;
}