Why does jslint shout at me?

My code is the following (also availa开发者_高级运维ble at jsfiddle):

$button = $('<button />', {
    text: 'my button',
    class: 'button'
});

The jslint error message is:

Problem at line 3 character 5: Expected an identifier and instead saw 'class' (a reserved word).
class: 'button'

---

Class is a reserved word for Javascript 2.0, thus you should not use it as a key in an object without putting it between quotes to mark it as a string.