js e.target.classlist code example
Example 1: add multiple classList
element.classList.add(class1,class2,class3...);
Example 2: classlist
// use the classList API to remove and add classes
div.classList.remove("foo");
div.classList.add("anotherclass");
Example 3: css class list
var myElement = document.getElementById("myElementID");
myElement.classList.add("style1 style2");
myElement.classList.remove("style1 style2");