javascript disable back button code example

Example 1: disable back button in browser

<script type="text/javascript">  function preventBack() {window.history.forward();}  setTimeout("preventBack()", 0);  window.onunload = function () {null};</script>

Example 2: how to disable back js

history.pushState(null, null, null);
$(window).on("popstate", function (event) {
  if (!event.originalEvent.state) {
    history.pushState(null, null, null);
    return;
  }
});