javascript remove from class list code example

Example 1: add multiple class list at once in js

elem.classList.add("first");
elem.classList.add("second");
elem.classList.add("third");

is equal to :

elem.classList.add("first","second","third");

Example 2: js remove class

const removeClass = (element, name) => {
    const pattern = new RegExp('(?:^|\\s)'+ name + '(?:\\s|$)', 'g');
    element.className = element.className.replace(pattern, "");
};