set timout for a div code example

Example 1: set timeout javascript

setTimeout( () => {
 	alert("J'aime les chats"); 
}, 2000);//wait 2 seconds

Example 2: how to set timeout for a div tag in html

<script>
  const timeout = document.getElementsByClassName('classname')
  setTimeout(hideElement, 1000) //milliseconds until timeout//
  function hideElement() {
    timeout.style.display = 'none'
</script>
<div class="classname">
  <span> &times; </span>