what DOM nodes accept class name code example
Example 1: get elment by id within get element byclassname
var targetDiv = document.getElementById("foo").getElementsByClassName("bar")[0];
targetDiv.textContent = "Goodbye world!";
Example 2: element.classname javascript
let el = document.getElementById('item');
if (el.className === 'active'){
el.className = 'inactive';
} else {
el.className = 'active';
}