JavaScript CSS how to add and remove multiple CSS classes to an element

Question

How can assign multiple css classes to an html element through javascript without using any libraries?

Answer 1

Here's a simpler method to add multiple classes via classList (supported by all modern browsers, as noted in other answers here):

div.classList.add('foo', 'bar'); // add multiple classes

From: https://developer.mozilla.org/en-US/docs/Web/API/Element/classList#Examples

If you have an array of class names to add to an element, you can use the ES6 spread operator to pass them all into classList.add() via this one-liner:

let classesToAdd = [ 'foo', 'bar', 'baz' ];
div.classList.add(...classesToAdd);

Note that not all browsers support ES6 natively yet, so as with any other ES6 answer you'll probably want to use a transpiler like Babel, or just stick with ES5 and use a solution like @LayZee's above.