is visible javascript code example

Example 1: how to make div visible and invisible in javascript

elem.style.display = 'none'; // hide
elem.style.display = 'block'; // show - use this for block elements (div, p)
elem.style.display = 'inline'; // show - use this for inline elements (span, a)

Example 2: js check if element hidden

if (elem.getAttribute("hidden") != null){
  //code if elem is hidden
}