There are many ways can do that!
jQuery
remove all class
$("element").removeClass();
OR
$("#item").removeAttr('class');
OR
$("#item").attr('class', '');
OR
$('#item')[0].className = '';
remove multi class
$("element").removeClass("class1 ... classn");
OR
$("element").removeClass("class1").removeClass("...").removeClass("classn");
// remove all items all class _x000D_
const items = document.querySelectorAll('item');_x000D_
for (let i = 0; i < items.length; i++) {_x000D_
items[i].className = '';_x000D_
}
_x000D_
// only remove all class of first item_x000D_
const item1 = document.querySelector('item');_x000D_
item1.className = '';
_x000D_