convert jquery to javascript

// With jQuery
$(document).ready(function() { 
  /* Do things after DOM has fully loaded */
});

// Without jQuery
// Define a convenience method and use it
var ready = (callback) => {
  if (document.readyState != "loading") callback();
  else document.addEventListener("DOMContentLoaded", callback);
}

ready(() => { 
  /* Do things after DOM has fully loaded */ 
});