javascript hide scrollbar

/* Hide scrollbar for Chrome, Safari and Opera */
.example::-webkit-scrollbar {
  display: none;
}

/* Hide scrollbar for IE and Edge */
.example {
  -ms-overflow-style: none;
}

/* On Chrome */
.hide-scrollbar::-webkit-scrollbar {
    display: none;
}
/* For Firefox and IE */
.hide-scrollbar {
    scrollbar-width: none;
    -ms-overflow-style: none;
}

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;
} 

  /* Hide scrollbar for Chrome, Safari and Opera */

  .example::-webkit-scrollbar {
  display: none;
}

/* Hide scrollbar 
  for IE and Edge */
.example {
  -ms-overflow-style: none;
} 

function HideScrollbar() {
  var style = document.createElement("style");
  style.innerHTML = `body::-webkit-scrollbar {display: none;}`;
  document.head.appendChild(style);
}