JAVASCRIPT

classlist add js to add more than one class

// to add
elem.classList.add("first", "second", "third"); // or,
elem.classList.add(...["first","second","third"]);

// to remove
elem.classList.remove("first", "second", "third"); // or,
elem.classList.remove(...["first","second","third"]);

add multiple classList

element.classList.add(class1,class2,class3...);