Question

Is there a way of checking whether the object’s specific class is in array – I’ve done it with object’s ‘id’, but can’t do with ‘class’ – with ‘id’ it goes like this:

var arr = [ 'error', 'button', 'items', 'basket' ];
if (jQuery.inArray($(this).attr('id'), arr) == -1) {
      // do something here
}

I would like to have something like the following, which doesn’t work:

var arr = [ 'error', 'button', 'items', 'basket' ];
if (jQuery.inArray($(this).attr('class'), arr) == -1) {
      // do something here
}

Any idea?

Just to show you what I’m using it for:

var arr = [ 'error', 'button', 'items', 'basket' ];
$.each(data, function(k, v) {
    if (jQuery.inArray($(this).attr('class'), arr) == -1 && $('.' + k).length > 0) {
        $('.' + k).fadeOut(100, function() {
        $(this).hide().html(v).fadeIn(100);
        });
    }
});

Answer 1

$(this).is(
     [ 'error', 'button', 'items', 'basket' ]
     .map(function(cls) {return "." + cls;})
     .join(',')
);

1. $(this).is(selector) checks if the given object or set of object matches the selector.
2. To construct the selector we take an array of the classes were interested [ 'error', 'button', 'items', 'basket' ]
3. As the classes are selected with .<class_name> we prepend the dot to each class name using map array.map(function(cls) {return "." + cls;})
4. To make this a full selector we can join the array elements using a comma as a separator with array.join(',')

The result is $(this).is('.error, .button, .items, .basket') which matches if $(this) has any of the classes defined.