Pass array of classes to `.addClass()`, `removeClass()`, and `toggleClass()`

[t-kelly]

Description

It would be great if these examples:

var class1 = 'class-one';
var class2 = 'class-two';

$('.element').addClass(class1 + ' ' + class2);
$('.element').addClass(class1).addClass(class2);
$('.element').addClass([class1, class2].join(' '));

could instead be written like:

var class1 = 'class-one';
var class2 = 'class-two';

$('.element').addClass([class1, class2]);

[timmywil]

For the most part, we're not looking to add signatures or new features to jQuery, but I don't hate this. It has parity with libraries like React and Angular.

[dmethvin]

Note that this can already be done by $('.element').addClass([class1, class2].join(" ")); which isn't that burdensome. It will take more bytes than that to do this inside jQuery.

[mgol]

@dmethvin

Note that this can already be done by $('.element').addClass([class1, class2].join(" ")); which isn't that burdensome. It will take more bytes than that to do this inside jQuery.

It's true but it's also uglier. :)

I like this proposal because:

1. We don't currently accept arrays as any parameter to class methods so there should be no confusion. Because of that, it shouldn't also add that much code to jQuery.
2. Accepting classes will align us more with the classList standard and aligning with standards is A Good Thing.
3. It will allow to pass unprocessed class arrays to jQuery from other libraries/frameworks that use the array syntax.
4. (This one is a bit of a stretch, but...) If we ever drop IE and start using classList instead of classNames everywhere, this would be a more natural signature and the space-separated values would be the ones that requires more pre-processing.