How to change elements class using Javascript

If you want to replace all classes of an element, then

document.getElementById("ElementName").className = "ClassName";

If you want to remove a class from an element, then

document.getElementById("ElementName").className =
   document.getElementById("ElementName").className.replace
      ( /(?:^|\s)ClassName(?!\S)/g , '' )

If you want to add additional class to element, then

document.getElementById("ElementName").className += " ClassName";

You can use above code as per your requirements.

To Add, Remove or Remove Class from element using  jQuery, you can refer below lines:

$('#MyElement').addClass('MyClass');

$('#MyElement').removeClass('MyClass');

if ( $('#MyElement').hasClass('MyClass') )